To be true Screen Overlay is basic feature used by almost every application.
Messenger Chat Head, Inbox Messages Preview and Whatsapp Messages Popups are all example of screen overlay feature, so you cant uninstall all application to resolve Screen Overlay Detected popups on your device…
You just need to manually turn of screen overlay of all applications in your device, Follow following settings to turn off screen overlay of android application:
Click on Three Dots (Top right corner) & Select Draw Over Other Apps
Turn off screen overlay of all apps one by one
This must solve the issue of screen overlay in your device…
If this isn’t solving then screen overlay issue in your device or you haven’t got my answer then refer to below reference:
how to turn off screen overlay