Reloading the game would give the player and AIs a free movement turn. In which the production / research will not be advanced. This happens almost everytime and easily recreatable.
How to recreate it :
Save a game with one of the planets having active production queues, record the weeks left for the current production.
Reload a game and make a turn.
Verify all available ships are given a new turn's movement points, and the production progress remain the same