[2020] macOS retina resolution not working

This is an issue on recent MacOS versions I"m afraid, not all resolutions display properly.

Open up the file documents/paradox/stellaris/logs/system.log , at the end of that are the supported resolutions for your hardware. One that should always work is your Mac's desktop resolution; for others listed there you just have to try them to see which ones work okay on your setup - usually about half of them. You may find that switching to borderless or windowed mode helps too.

Sorry for that problem!