Membership Level Not Saving Properly

Im having a real annoying issue with Membership. (This is not Membership2.) Every couple days I have to log in and re-update a member to his appropriate member level. I change his member level, and within a day or two it somehow magically goes back to the default member level. I have had to manually change his member level at least 10 times now, and he is getting very angry, and so am I. I have no idea why his member level won't just stick???

And no I cannot just upgrade to Membership2. This theme is way too integrated with Membership Premium and totally breaks the site upon updating. I have a ton of custom membership functionality built into this theme to update. And unfortunately I'm stuck with this plugin. I've had way too many issues in the past with this plugin and am regretting ever using it in the first place.