Did another factory reset and it has been working flawlessly.
Just got my son's hand-me-down Inspiron 15 7559 that he used for gaming. I replaced the bad and swollen battery, cleaned it up, and ran "Windows Update", "Dell Update" and "Support Assist." All software and drivers are up to date, and there are no error messages. I even ran the F12 Preboot Diagnostic Test.. The system is functioning perfectly except upon start-up the buttons on the touchpad and double-tapping do not work properly for anywhere from 5-90 minutes. A USB wireless connected mouse has the same problem. This was a problem prior to battery replacement too, but less so with the use of a wired mouse. During this 5-90 minutes the cursor moves fine, but buttons and double tapping the touchpad only work to open apps in the task bar and the open the Windows start menu. It can also close apps by clicking the X for the app from within the task bar pop-up. Clicking X in the app window has no effect.  [IMAGE]   [IMAGE]   I can't even shutdown or restart the computer the standard way. I have to use Alt-Ctrl-Del to get to actionable options. Any suggestions? Update: I just restarted the laptop and got distracted for 10 minutes before touching any key. Upon signing in the touchpad button worked perfectly immediately. 
Dell Inspiron 15 7559 TouchPad Buttons Stop Working Temporarily After Booting