Artanis level coop dropped and capped

Hello to you thats reading this!
Ive recently came back a little to sc2, always liked coop and was getting artanis leveled up.
I m pretty sure i got him to 15, if not one level less. U could probably see that on replays or games played. And somehow the level dropped to 5 again. I imagine this is a bug.
I bought LOTV recently besides that idk what could be important to help. the lvl drop was after the buy.
Sry for talking too much, hope u can help me with this since its kinda annoying to lvl again, ty!