This has only been happening in MULTIPLAYER GAMES, and has consistently occurred in every one.
When the game automatically adds new items to a planet's construction queue after completing research, e.g. upgrading from Basic Factories to Xeno Factories, the game is adding the improvement twice. If you have 3 basic factories on a planet, the game adds 6 upgrades to the queue. The extras can be cancelled but this is tedious and cumbersome as your empire gets larger.
Is anyone else noticing this?