I feel you, my UI is also the same… and I can’t change the resolution at all because it’s greyed out :(
Kalleh24680 ConseraOfficial One of the patches changed fullscreen to a borderless windowed mode. I don't remember why they did it, I wasn't having any problems with my game's resolution. But anyway, have you tried the shortcut to make it toggle between regular windowed and borderless windowed? Alt+Enter. You can also force it into bordered windowed mode by (in the library view) clicking on the ... on Sims 2 and selecting view properties, then adding a -w to the advanced options field. Some players reported that after trying one of those, they were able to set resolution again.
I don't think they explicitly explain why they added borderless window mode in one of the patch note. But it makes sense why they added it. It's a modern display feature and makes some people lives more convenient. I'm loving it since I got a dual monitor setup and it makes multitasking convenient and I don't have to wait for my computer to unfreeze everytime I tab out
I also have a dual monitor setup, so I keep Sims 4 in windowed mode too.
Why in window mode if you have dual monitors? Your game looks better in fullscreen/borderless window mode
