After the first part of the Zhentarim fight i saved and went to bed then when I loaded up the fight the next day to kill the people on the other side of the bridge with the explosives and 2 locked rooms with chests, both Wyll and Astarian will no longer follow the party leader, I have to move them individually, iv tried chaining and rechaing to fix them, this did not work.
Traveling to a new zone does not fix it. full rest caused the whole game to crash
Reloaded the game and they are still bugged, saving the game now crashes the application too (this time)
Teleporting and full resting does not fix the bug - so this save is going to be pretty annoying to play with

Group hide does not work on them either