IntelliJ IDEA: how to disable projects opening as tabs on macOS?

Question

No idea since when this was introduced but recently updated to Monterey and it started to appear.

How can I disable it? I prefer one editor per workspace. The new way conflicts with normal tab switching.

Answer 1

Either disable it globally in macOS system settings, or disable it for IntelliJ IDEA only by adding ide.mac.bigsur.window.with.tabs.enabled=false in Help | Edit Custom Properties (IDE restart is required).