How to fix OnePlus 7 Pro display timeout auto reset to 15 seconds

OnePlus 7 Pro when updated to Android 11 has a bug to auto reset to 15 seconds timeout. However OnePlus 7 pro has got Android 12 upgrade and there isnl a setting which fixes this.

Got to Settings > Battery > Power Save Mode > Default Optimisations > Change 15s timeout setting.

Below are images for the same in same order

The toggle button has to be turned off "Change auto screen-off time to 15s".

I don't know if same if available in Android 11 ROM. If this setting is available then time out can be set to one setting everytime.