Given: Ship docked to shipyard.
Bunch of turrets docked to ship.

Action: I left the game.
Result: Upon return i can see cannons from my turrets floating 400 meters aside from place where they're supposed to be.

Action#2: I repaired my ship, using shipyard command, so i can get all missing turrets back in their places.
I left game after the end of construction.
Result#2: Different turrets are now missing, but with their bases too, not just part that supposed to shoot.

Action#3: Same as #2.
Result#3: Few turrets lost their cannons right after construction was finished.
Leaving sector changed nothing.
Leaving the game took away few more turrets.