Gained XP number super high when it shouldn't be

[NoShotz]

Even on login the XP gained number is super high before I have even done anything that would give me XP. This occurs on all my characters that aren't max level.

No lua errors are generated while the number is this high.

[NoShotz]

One thing to note, the gained XP number does go up when I gain experience, it just seems to not reset when I log off or reload my UI, so I'm guessing the number is the results of multiple levels worth of XP gain.

[NoShotz]

Do note, I am almost max level on all my characters, so I won't be able to confirm if the bug is fixed for much longer.

[DJScias]

One thing to note, the gained XP number does go up when I gain experience, it just seems to not reset when I log off or reload my UI, so I'm guessing the number is the results of multiple levels worth of XP gain.

This is actually a good thing to note, will help me narrow down what this might be about.
I've got a few ideas, but will have to check it out to be sure.

Do note, I am almost max level on all my characters, so I won't be able to confirm if the bug is fixed for much longer.
I, unfortunately, can't promise that it'll be resolved super fast as I have some RL to contend with in the coming days.
However I do have a few characters still myself to level and given the previous thing you pointed out I think I should be able to at least fix this even if I wouldn't be able to reproduce this.

Thanks again for the detailed report already, this helps out a ton in narrowing these things down.
It'll probably help me be able to quickly tackle this issue when my RL clears up (this shouldn't be too long).