My xp bar is glitched

I was playing my Java world earlier and I just noticed that no matter how much xp I collected, it didn’t make my xp bar go up at all. After I noticed this, I did EVERYTHING I could find to try and fix it and nothing worked. I tried restarting my computer, I tried resetting all the settings on my game, I tried making a backup and deleting my world and then opening the saved backup again only to find that nothing had changed. I’m making a lot of progress in this world and I’ve worked really hard on it. I would hate to lose it. Any suggestions??