@3d87c4 I can reproduce your observation. I didn't intentionally set project to 360 this morning. If I actually struck that key, it really was operator error. Maybe there is another trigger to the width change. With no other changes to Project Properties, I didn't get the error the first time I tried to set the project to 360.
Actually, I rarely use the 360 button, so I think it has more to do with either the large frame size or 3D stereographic projects (in my case).
I recently include this issue in a support request, but my ticket involved several other symptoms which were addressed by changing the NVIDEA settings to "compatible" & Magix closed my ticket without any real response.
Here's a thread I started that includes the 8pixel width bug & other issues:
@3d87c4 and @john_dennis This is really strange. Reproduced this problem yet. One thing that might help me out is for you to provide your preference file to me to analyze. That could indicate what might be going wrong here. Look in c:\users\(username)\AppData\Local\VEGAS Pro\20.0 and find the persist.prefs file.