Completely exist Ubisoft Connect and relaunch it, and it should update for you.
My testing thus far indicates progress. While the game did eventually crash to the desktop, it appears to be the "old" problem. Screen didn't hang or turn black and just die. So I do think they either rolled back UB Connect, or fixed it, and the problem of yesterday might be resolved. But the problem from before remains.
Regarding the "old" problem, in all the times my house experienced it, if you relaunch it usually plays fine for hours. So from my perspective it is lesser priority. Very important, and should have all hands on deck, but not the failure that was yesterday.