I am still having problems with units activating (flashing) once they are produced in a city.
I can manually check each and then manually activate them, but that would be a hassle later
in the game. I suspect no one else is seeing this.
As far as I know I have not heard of it being an issue..
However, If they are a land unit in a single island city, they will not be activated automatically (as they cannot move).
Send me an email describing how you get that first unit built.