I don't know if this bug has been already reported but when playing on an immense map with all the AIs, sometime when my turn is finished, the game become slow. Then, it's like if the turn of the computer was not yet finished but I can already start playing and construct buildings on my colonies.
For example, in the following screenshot I was able to create several Power matrix on the same tile:
If I return back to the main screen, the button "wait" is still visible during few seconds..
Can you check if you can reproduce this issue?