I’ve levelled up twice (on Xbox Series X) without the game crashing so it doesn’t happen every time. I have had a guildmate report this issue though.
One issue I did have with the level up screen is that it appears so suddenly, I accidentally selected which gem mastery to upgrade before I even realised I was levelling up.
I also had the game crash randomly, but not on level up. I’d finished a pet rescue and collected rewards then selected the troop menu. The game crashed before loading troops.
I have a theory that spamming a on the animation makes it crash. I wanted to try it when I last levelled but my reflexes got the better of me. It did indeed crash. Thats 2 crashes on level ups this weekend