I have just updated to V5.97 . When I click on ‘open project in new window’ and select an html folder I just get a window with nothing in it that says untitled.
So there is a bug that prevents me from opening two projects at once (I use this feature all the time). So I closed Pinegrow and decided to open the other project as on its own. However I discovered a second bug. When I close Pinegrow and then open it again to get back the main menu and open a different folder, instead it automatically opens the same project again. I have to close and open several times before I get back to the main menu.
macOS Catalina 10.15.5