Been having this same issue since 1.9 was released. Game will eventually unfreeze but connection to Microsoft account will have been lost. Haven't tested turning off WiFi but then I can't play with my friend, which is half the reason I play....
Attached image appears after game has unfrozen. Microsoft account has been disabled and friends can no longer join game.
No this was single player. I had just downloaded the new 1.6.1 and wanted to play a single player game to check out the new content. The first time it crashed, the game had not fully loaded (the chunks were still loading), so I relaunched the game and tried again. It lasted a little longer, but crashed after maybe a couple minutes.
I just tried playing the game again and didn't experience any crashing.
I have this same issue. It also seems to happen quite often when Saving and Exiting my world.