poe 2 options windowed full screen not saving

Same... driving me crazy!

Same here for poe2, and it does the same in poe1 for maybe 2 leagues :-/

+

10 Months no fix? Yikes.

Still an issue. Every time I restart the client the setting reverts from "Windowed Fullscreen" to just "Fullscreen"

it's probably nvidia. If you let the nvidia software optimize your graphics setting it changes it to "fullscreen (recommended)" at every start.

I encountered the same issue. In my case, the problem was resolved by removing the Read-only attribute from the poe2_production_config file located in Documents/PoE2.
After doing this, I was able to change my settings, and they were saved consistently after each change.