I have noticed this after the big UI update (the one that put the 'Steam Client is up to date' in a big banner across the bottom of the window) but the Menu Bar (as in Apple Menu, Steam, Account, View, Friends, etc..) is rendered inaccessible after using the Steam Client.

This occurs while using the Steam app. I spent enough time to post something to another discussion via the Steam app and wound up losing access to the whole set of menus. Keyboard shortcuts still work. Exiting Steam and alt-tabbing restore access to the menu items for a time.

Perhaps this is related to how a context menu item (such as copy) will persist on screen and refuse to be dismissed until you select an option from it? To trigger this, perform the secondary click action and then click anywhere else and watch it not disappear.

I have not experienced this behaviour in any other application on the Mac thus far.

I am currently using Sonoma 14.3.1 but this also occurred while using Ventura.