Hi @Scuba_Stevo72 - Thank you so much for keeping us updated. So happy we got the windowed screen to work, at least for a bit. I can tell you for sure that SimCity does not like ultra-HD settings, PCs also have this problem (game was built when HD 1920 x 1080 settings were the highest you could get). Also doesn't play well with most multi-display settings. You could check to make sure your display settings on the Mac don't have any multi-display settings enabled even if you don't have dual monitors. Sometimes PCs will default on install to double monitor settings for some reason - doesn't make a difference for the computer, but the game has trouble recognizing something.
Do you have an option in SimCity settings to choose 1920 x 1080 resolution? If you can choose that resolution, then check the box underneath that says "full screen" you should be able to run in full-screen windowed mode at those settings. If it looks good like that, you *should* be able to remove the "-w" from the startup options and have it start up at HD resolution and full screen.
Having said all of that, do you have any issues on the computer with the new mouse or keyboard? Doesn't seem like it should impact it, but as you said before - updates and new stuff can screw up in all sorts of ways.
There was one more tip I found that was related to a different game and different OS version, but helped some users. I have no idea why this would have an impact, kind of a shot in the dark, but I don't think it would hurt to try. Go to System Preferences > Security & Privacy > Privacy > Accessibility and check SimCity. If this helps, I would be very interested to know it lol.
I'm asking around with the helpers to see if there's a Mac expert who may have an idea on what to try. I will get back with any other ideas.
