Q:

CardView disappearing on API 19

I have developed an app that works perfectly on Lollipop. However, I am experiencing some strange glitches on kitkat (api 19)
When I run my app on the kitkat device, it shows my card view for a split second then it disappears.
below is my xml layout:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:map="http://schemas.android.com/apk/res-auto"
    xmlns:bootstrap="http://schemas.android.com/apk/res-auto"
    xmlns:fontawesometext="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="0dp"
    android:paddingLeft="0dp"
    android:paddingRight="0dp"
    android:paddingTop="0dp"
    tools:context="com.running.mattboyle.runnertoolbox.RunningMap">

    <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_viewrunning"
        android:layout_gravity="center"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"

        android:background="@drawable/backgroundcard"
        card_view:cardCornerRadius="4dp">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <Chronometer
            android:id="@+id/Duration"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="16dp"
                android:paddingLeft="10dp"
            android:text="0:00"
            android:textAppearance="?android:attr/textAppearanceLarge" />
        <TextView
            android:id="@+id/Calories"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="14dp"
            android:layout_marginTop="60dp"
            android:text="Calories: 0" />
        <TextView
            android:id="@+id/pace"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="60dp"
            android:layout_alignParentRight="true"
            android:text="0:00"
            android:layout_marginEnd="60dp" />

            <TextView
            android:id="@+id/paceunits"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="60dp"
                android:text="min/km"
                android:layout_alignParentRight="true"
                android:layout_marginEnd="10dp" />

            <TextView
                android:id="@+id/distanceText"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignStart="@id/Duration"
                android:layout_marginTop="52dp"
                android:text="0.00"
                android:textAppearance="?android:attr/textAppearanceLarge" />

            <TextView
                android:id="@+id/distanceUnits"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@+id/Duration"
                android:layout_marginTop="12dp"
                android:layout_marginLeft="5dp"
                android:layout_toRightOf="@id/distanceText"
                android:text="KM"
                android:textAppearance="?android:attr/textAppearanceMedium" />

        </RelativeLayout>

    </android.support.v7.widget.CardView>

    <fragment
        android:id="@+id/map"
        android:name="com.google.android.gms.maps.MapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        >

        <com.beardedhen.androidbootstrap.BootstrapButton
        android:id="@+id/runButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="5dp"
        android:text="Begin Run"
            android:layout_centerInParent="true"

        bootstrap:bb_type="primary" />

    <com.beardedhen.androidbootstrap.BootstrapButton
        android:id="@+id/pauseButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="5dp"
        android:text="Pause"
        android:layout_centerHorizontal="true"
        android:paddingRight="120dp"
        bootstrap:bb_type="warning" />

    <com.beardedhen.androidbootstrap.BootstrapButton
        android:id="@+id/EndButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="5dp"
        android:layout_centerInParent="true"
        android:layout_centerHorizontal="true"
        android:paddingLeft="120dp"

        android:text="End Run"
        bootstrap:bb_type="success"

        />
    </RelativeLayout>

    <RelativeLayout
        android:layout_height="wrap_content"
        android:layout_width="fill_parent"
        android:layout_alignParentBottom="true"
        android:paddingBottom="40dp">

        <com.beardedhen.androidbootstrap.BootstrapButton
            android:id="@+id/right"
            android:layout_width="70dp"
            android:layout_margin="10dp"

            android:layout_height="wrap_content"
            bootstrap:bb_type="primary"
            fontawesometext:fa_icon="fa-forward"
            android:text="Next"
            android:layout_alignParentRight="true"
            android:layout_marginEnd="10dp" />

        <TextView
            android:layout_marginTop="15dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:text="Calculating....."
            android:id="@+id/runLength"
            android:layout_centerHorizontal="true" />

        <com.beardedhen.androidbootstrap.BootstrapButton
            android:layout_width="70dp"
            android:layout_height="wrap_content"
            bootstrap:bb_type="primary"
            android:text="Last"
            fontawesometext:fa_icon="fa-backward"
            android:id="@+id/left"
            android:layout_alignParentLeft="true"
            android:layout_marginStart="10dp" />

    </RelativeLayout>

</RelativeLayout>

What's extra weird is I have a cardview on my home screen too that opens and works just fine:

      <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
            android:id="@+id/card_view"
            android:layout_gravity="center"
            android:layout_width="match_parent"
            android:layout_height="180dp"
            android:background="@drawable/backgroundcard"
            card_view:cardCornerRadius="4dp">

            <RelativeLayout
                android:orientation="vertical"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:divider="@drawable/vertical_divider"
                android:dividerPadding="12dip"
                android:showDividers="middle">

                <TextView
                    android:id="@+id/weather"
                    android:textColor="@android:color/primary_text_light"

                    android:paddingTop="10dp"
                    android:paddingLeft="15dp"

                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"
                    android:text="Weather"
                    android:textSize="25dp"

                    />

                <TextView
                    android:id="@+id/location"
                    android:textColor="@android:color/darker_gray"

                    android:paddingTop="130dp"
                    android:paddingLeft="40dp"

                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"
                    android:text="Birmingham,UK"

                    />

                <ImageView
                    android:layout_width="130dp"
                    android:layout_height="130dp"
                    android:background="@drawable/nightcloud"
                    android:layout_marginTop="25dp"
                    android:layout_marginLeft="20dp"
                    android:layout_centerVertical="true"

                    android:id="@+id/weatherImage" />

                <TextView
                    android:id="@+id/low"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="05\u00B0"
                    android:paddingTop="75dp"
                    android:paddingRight="20dp"
                    android:layout_alignParentEnd="true"
                    android:textColor="@android:color/primary_text_light"

                    />

                <TextView
                    android:id="@+id/high"
                    android:textColor="@android:color/primary_text_light"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="10\u00B0"
                    android:paddingTop="95dp"
                    android:paddingRight="20dp"
                    android:layout_alignParentEnd="true" />

                <TextView
                    android:id="@+id/current"

                    android:textColor="@android:color/darker_gray"
                    android:textSize="50dp"

                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="10\u00B0"

                    android:paddingRight="50dp"
                    android:layout_centerVertical="true"
                    android:layout_alignParentEnd="true" />

                <TextView
                    android:id="@+id/judgement"

                    android:paddingTop="10dp"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textColor="@android:color/darker_gray"

                    android:text="Wear an underlayer, it is cold!"
                    android:paddingBottom="5dp"
                    android:paddingLeft="15dp"

                    android:layout_alignParentBottom="true"
                    android:layout_alignParentStart="true" />
            </RelativeLayout>

        </android.support.v7.widget.CardView>

Log cat doesn't offer any complaints.
Android Studio documents this too:

Api 19

api 21
Any ideas? Would really appreciate any assistance. 
EDIT: I tried adding the line           findViewById(R.id.card_viewrunning).setVisibility(View.VISIBLE); to no prevail.
Once again, this works perfectly on an api 21 device. Very strange one. 

A:

Look at the component tree tab on the right in android studio for your layout in v19. Select your cardview and look on the visual editor, it should be highlighted. My guess is it's hidden behind the fragment.

