I find this very curious, since it looks like only some of us are seeing this. Since I am not seeing this, I have to wonder if it is somehow tied to what hardware we are using and the way GC3 uses it.
While I am aware that there is a lot of work to be done with the graphics in GC3, perhaps there is something they missed in some of the quirks there are in using the many variations of hardware we have. Or, perhaps there is something to the warning to have the latest GPU driver installed. DirectX level 11 is supposed to keep programs like GC3 from having to be sensitive to the various hardware combinations we could use, but it is even possible to mess that up as well.
So, the first question is to the GC3 Dev team: Is this a known problem?
The next question is to moltobenny: Are you running with the most current (non beta) GPU driver? (I had some problems with the latest GeForce beta level GPU driver and had to back it off.)