Last point of the XP cap

[Loreweaver]

Hello, I noticed last month that when I got to my xp cap I couldn't get the final point so I was only able to get 2999 xp that month. I didn't think much of it at the time because it's just one xp but now it's the one point of xp I need to get a level. Not sure why it's happening I've tried a few smaller dungeons on my own though, I get the overcome challenge message but no xp.