TwentyTwentyTwo theme Custom Menu disappears

The new 2022 theme has some great features. The issue I am having is that after I create a custom Menu and add it to the Header template part, it was working fine until the nav items suddenly stop showing. So I created another new custom menu and added that to the header template, that worked for a while and then disappeared at some point. (I may have been fixing typography and colors when this happened.) The Navigation shows up as part of the List view in the template body, but the nav items seem to have disappeared. If I add a new link to this menu, it shows up, but the initial nav items are all gone. I have now chosen one of the predefined Menus that came with the WP install for now and that shows up fine ( at the time being).
Anyone had this issue? Maybe I am not saving the menu correctly? Or maybe its a bug with the Beta version of the 2022 editor?