At first I thought it's related to the Fjords map but it happened on other ones as well
I don't see the XVM patched loading screen. I see the regular vanilla one but no tanks. Just 2 empty slots with 2 tank silhouettes, one for each team.
After that it either crashes the client or it stays stuck indefinitely and I can press ESC and exit the battle.
As soon as the battle is over, I can play normally, until I get another map that won't load.