Is it me or pixies are bugged? even though I ticked all the boxes they don't really take the milked slaves out of the milking room or put the new girls into the capsule room.
Not having an issue with either of these things.
Did you manually add them to the milking room, or did you interact with the slaves while milking? Those seem to stop the pixies from moving them back after milking.
As for the capsule room, the only reason I can think of is you do not have capsule maintenance ticked for pixies on the overhead bar (click the + symbol) or all girls do not have it ticked (I think this is on by default though).
Otherwise, do you have enough pixies to move them? I think they prioritize some tasks, and can only perform one at a time, they will wait for birthing to finish before moving to a new task after moving a slave back.