Changes (to controls, video settings, audio, etc) not saving when I close Minecraft

I’ve recently noticed that whenever I close my game, any changes I made during the time I was playing do not save. I do not know about vanilla worlds since I play servers only.

I noticed a while back that whenever I tried to activate flame particles, as soon as I close the game they’d become deactivated again. This goes for texture packs too, when I’d deactivate a Hypixel texture pack it would seemingly reenable reenable when I opened the game again.

My friend recently started a 1.16.5 SMP. As a Hypixel player I use 1.8.9 optifine but I want to have more fun so I switched (or at least tried to) to unmodded, no optifine 1.16.5, but it keeps resetting the controls, the video settings, even the "Do not show again" on the third party server warning. For some reason though, my 1.8.9 controls carry over to 1.16.5, even though they didn’t carry over when I was still playing 1.14 vanilla (but that was more than a year ago).

I do not have java installed anymore to save space, would that be a problem?

Help is appreciated, thanks!