I've never tested pitboss, and never played multiplayer without human players, so I'm not sure what would be causing the issues. I'd suggest if you want to play SP, to just do it regularly through the menu (the modpack allows you to play it through there as well as MP).None human players, because I just wanted to test it shortly. Maybe I have time in the next few weeks to try a game with human players.
As for multiplayer, if you ever encounter one player not being able to move or a stalled turn (this usually happens when first loading into the game for my friends and I) just have the player that cannot move exit to main menu and then invite them back. This fixes the issue 99% of the time in my experience. If not, try to do a full reload or an autosave a turn back. Other than that, the problem could be with pitboss. I've only ever done hybrid sim turns, not pitboss.