When reinstalling Minecraft on Xbox, settings don't save due to there being no functional options.txt file in the game folder, and players are inable to add this file themselves as the entire game folder for Minecraft Xbox is hidden and completely inaccessible. To quickly reproduce this, literally just adjust your game settings, then reinstall the game, and you will notice your settings got reset to default. 

This issue has existed since October 5th, 2022, when the Xbox version of the game was converted from UWP to GDK and the game folder was made completely inaccessible.