macOS out of the box fucking sucks for monitor scaling with third party monitors. It's honestly laughable for a modern OS. You can install some third party software that fixes it completely, but it really shouldn't be necessary. I use an (admittedly pretty strange) LG DualUp monitor as a secondary, and out of the box macOS can only make everything either extremely tiny, extremely large, or blurry.
Other than that, I've had no problems at all, and the window scaling between different DPI monitors is a lot smoother than it was with Windows previously.