Sorry for the spam, but as a guest I cant edit my post and I had to fix the image link (mods: please delete the first post, thank you very much).
I'd like to report that I do not gain any experience after any duel whatsoever (it doesn't work against bots nor humans).
Below I have a screenshot with an example. I have leveled up to the shown level about 3(?) month ago and returned yesterday to my account, only to find myself unable to gain experience?!