Remove Pop Up Ads / Adware / Malware / Madware from your Android Device. Find the Offending App and remove it. Unfortunately, turning off Ad (Advertisement) Personalization only works for some cases. This will work for ALL cases. Here I use a Google Pixel running Android 7 (Nougat). This method uses the adb tool, which is simple & free.
How To Remove Pop Up Ads & How To Block Ads On Android
Linux commands used over ADB:
dumpsys window windows | grep -E 'mCurrentFocus|mFocusedApp'
top -m 20 | grep u0