First, I agree if it is mistakenly offering an inappropriate update, it should be fixed. Are you getting the pop-up notification asking for what device was plugged in? You did not mention what audio device is showing in the Device manager, but I will assume it shows Cirrus instead of what shows below. The Realtek, if present, may not be exactly the same since I have an older system.  No Dolby Atmos on mine! [IMAGE]  
I have Cirrus Audio Controller. The DU (Dell Update) app recommends installing Realtek Audio. Please fix this, or add the function to permanently hide recommendations.    
Inspiron 14 5420, DU recommends wrong Audio driver