Sometimes after a fight I lose control of the fighter. I can highlight/select them but get no power/selection pop-up and they cannot move. Save and reload resolves it.

 

Exact same problem here.  Would a save game upload help?  I've started from a save point in the Dyfor Crossing three times now, and each time, after my first skirmish with beetles, the fighter no longer responds to commands effectively breaking the game since I can't leave the map area without him coming to the border.

I had the exact same issue with the fighter getting stuck after combat with the beetles.