BUG: Unable to save any settings

Title is mostly self-explanatory. I've tried multiple methods online on how to fix this issue, but every time I close out of the game and reopen it, all my settings have been reverted to default.

Could you please be more specific ?
Have you hit Apply after you changed your settings ?
Which exact settings are not saving for you ?
Have you tried to disable Steam Cloud to see if that's the issue ?