Screen timeout problem.

Yes I know how to change the settings... but..

My son had me install TikTok for the vids he keeps sending/sharing with me.. While using it, some pop up notification came on and asked me to allow the screen to stay on while watching the videos.. and I clicked [OK] or whatever the (agree) setting was.

Since then, if I pause on a video to resume watching it later on, the screen never times out.

With youtube for example, if I do the same, the screen WILL timeout as needed.

Yes, I've gone to Settings>Display>Sleep and changed it to various different times, but that has no effect on it.

I've deleted the app numerous times and it still keeps the screen active while paused.

Is this normal for this app?

Cheers!