Do i have to restart Unity Hub in order to switch to a different project?

I am running Unity Hub 2.3.0 on macos 10.15

When I open project A from Unity Hub. Then project A opens in corresponding Unity editor. Now say I want to close project A and open project B. When I close project A and switch back to Unity Hub, no Hub window is visible. And most submenus are greyed out. Thus I cannot open project B from Hub. I first have to. restart hub in order to make the Hub window with the list of projects appear again.

Is there a proper way to close a unity project so that Hub window is still visible? Am I Missing something?

This sounds like a MacOS compat problem, please direct your question to Unity directly.