SP version of mission. The usual vanilla regroup command doesn't seem to fix. The squad members seem to be leaving the squad - the white hexagon marker for each unit will disappear after certain command.
The Squad Regroup is an Extraction specific feature - I don't think it's a specific AI command, but I think just a way of advancing the time in the mission (sit at the campfire, game time advances an hour or so). But I've tested both ways and it seems that if you use the manual feature to advance time or the mission structure advances the time, it seems to introduce a hiccup in SOG AI.
I've played SP Extraction extensively several months ago and it worked great. Appreciate the response and anything you can do. Going back to your change log notes on Nov 1 it seems like it may be related AI units leaving the group and rejoining. Maybe something in the Extraction code that breaks the mod when it advances game time.