Crashes are always horrible. I’m sorry they happen so frequently in your game.
Did you try the steps mentioned in the official Resolving Crash Issues guide? If you haven’t, they might help a lot.
So your game crashes after you went to canvas in-game and head back to the lobby + it crashes when you did gameplay on an existing save file and head back to the lobby? Do you notice any framedrops, lags or glitches during gameplay or while browsing canvas?