I also saw people on reddit claiming (with screenshots) that the Sneak Attack mechanic is sometimes buggy in the new patch, but I myself haven't run into problems yet.
It definitely has some bugs, it's usually after an enemy has been hit with a spell (from what I've seen). The game won't let you get sneak attack through Threatened. There is a workaround if you have shared initiative where you can hit the enemy with a weapon, and then you can get sneak attack on the turn.
