Bug/Issue 2 units on the same tile in 2v2

When you play 2v2 with Fog of War turned on and your teammate intends to walk on a for him unseen tile with one of your own units on it they two units will end up being on the same tile
There seem to be some inconsistent bugs with not being able to select the initial unit anymore until the 2nd unit is moved away.
In short:
Player 1 unit on tile A
Player 2 (in the same team) moves unit on tile A while not having vision of it
Both units are on the same spot, Player 1 (sometimes?) can't move/select his unit until Player 2 moves his unit away