my fleet kam has a universal LT, after swapping zones a few times, i was able to in a space map slot a boff in the universal station, and then in the station i wanted him to be in. it had to be in the universal seat first. that universal seat was at the top of the list, so that might have mattered more then that it was universal, don't know. good luck
If you have a default small craft set, the universal station on it that might work too (has for some, but not others).
Having this problem account wide on all ships, tried just about everything from switching ships to relogging but didn't work. Flew to memory alpha to see if it worked there, but couldn't access the system, probably due to the crystalline entity parked on top of it.
Went to fleet starbase after that and found I was able to reassign BOffs there. Weird that it works in some systems and not others. Potentially game-breaking for a lot of people and needs to be fixed immediately.
I discovered this after buying a new Advanced Escort. In Sol System (or my shuttle bridge, I forget which) I was able to slot my science officers. In Alpha Centauri space I was able to slot the tactical officers. (though I had to do the top one first) I had to go to Memory Alpha system to slot my single Engineer station. I can't select None and get it to stick most of the time, and this bug is also affecting my Danube Runabout to some extent. Not sure if this info will work for anyone else, but I thought I'd share it. I think I'll still try and do a ticket to make sure they know it's bugged the heck up.