Reached mastery level 6, but it doesn't show up ANYWHERE.

So I reached mastery level 6 on Katarina a few days ago (lol sad) and it clearly said at the end of the game that I reached mastery level 6. When I went and saw on my profile, it still said I was only lvl 5, and I thought it would correct after a few days. So, 4 days later, and it says NOTHING. I tried in custom to play with her to see if anything showed up but nope :/

Please help! If I have to report the problem, where do I do that? :(