Some examples.
App is Simple File Manager - when I try to upgrade it says The privileged permissions have not been granted to the extension!
F-Droid update - error installing F-Droid (same as above)
YouVersion Bible App - The apk is split. Choose root or privileged installation method
Re-installing F-Droid to record what I do:
Click on Download F-Droid
Downloaded apk
Install F-Droid
Open F-Droid
Updating repositories
Now running updates
First update is F-Droid - bizarre because I just downloaded the latest version and it comes up with the error privileged permissions have not been granted.