@ToxicViolets It almost certainly matters that you're playing on a Mac. Please also list your computer's full specs: everything under About This Mac except for the serial number.
You could try playing with the graphics settings a bit to see if you get different results, for example using the default ultra profile (where it says Custom in your screenshot) or disabling post processing. I can't see whether you have laptop mode enabled—you'd need to scroll down a bit—but if so, definitely disable it first. It's supposed to be for low-end machines, and when it's enabled, the game cuts a lot of corners with rendering.
If the above doesn't help, you may be better off asking on a dedicated creators' forum, for example the one at Sims4Studio. I'm not aware of any issues with alpha cc and macOS, and the other Mac person I asked isn't either, but cc creators would have a better idea.
I've moved this thread to the general discussion section since it's not a PC tech issue and probably not a problem with your Mac itself.
@puzzlezaddict Ah okay, I honestly know nothing about computers so apologies! Here should be a screenshot of all of my specs.
@ToxicViolets That's not the info I was asking for; I wanted the initial pop-up when you click About This Mac. But the model number in your screenshot gives me a good enough idea.
I still think it would be useful to try the default ultra graphics profile both with and without post-processing; make sure laptop mode is disabled as well. And try both fullscreen and windowed modes. You'll need to quit and restart the game for the changes to take effect, other than fulllscreen/windowed.
