Can't choose Champion after battle

Hey there, I'm new to LoL after several years so my terminology might be wrong. I also couldn't find a more relevant board to post to, so I apologize for the irrelevance. But after winning a game and I think completing a quest, I can choose between three champions for their shards. However, the buttons "view abilities" and "select" do not appear when my mouse cursor is in the right spot. Instead, they only appear when my mouse cursor is below them. If I try to move my mouse cursor to the buttons, they disappear, and I cannot press them. Thus, I am stuck at this screen. I've tried resetting LoL and my PC, but nothing changes.