Not sure if this is linked to the over-running pop issue but:
Queued 10 traders to build as many as I could without calculating.
Queue showed up with 5 traders in which was fine.
Seemed as if it started building.
Got to 0 turns, won’t complete and the - is there to take out of queue but doesn’t work.
If add other ships in I can’t rearrange the queue but can take the new ships out.
Might have something to do with this: