Hello,
I'm using primararly the new argonian companion, and sometimes in the world he just stop to attack, but seems to be only it's animations. then the mob die at 50% of life because it seems that the damages companion did count after all...
Also I was in a dungeon two days ago with a friend, and we were both with our companions, argonian one for me, khajiit one for her. For the last boss, our companions just stop doing anything but saying *** to us, instead of attacking. they just followed us, not taking damage too. We noticed it much time after so we respawned them and it was ok then. But all the dungeon long there was no problem before.
The dungeon was the Depths of Malatar.
Last thing, my mate experienced yesterday a bug where she was NOT with khajiit (or any) companion, then she got caught stealing, and the relationship of the khajiit companion downed.
There are more and more bugs with companions doing uncoherent things.