I'm not sure what happened but everything I had done to get the new "Editor" and "Browser" style of navigation bars to work for my app on Catalyst has totally broken on the latest beta for Ventura.
My app is using a UISplitViewController as the root view controller, and previously if I changed which view controller was representing the content then the buttons represented by its navigation item would update in the toolbar.
Now all I see is the buttons from the first view controller's navigation item remain after a view controller changes.
I have occasionally seen the buttons update to a different view controller's navigation item, but after that happens the buttons also no longer work. It's like they're being tapped on but nothing happens.
Just to reiterate, all of this was working perfectly fine on the last beta and I haven't made any code changes since updating my Mac.