I have an Objective-C app which ran OK on Catalina in Xcode 12.3 on a 2012 Macbook Pro. Since App Store will now only accept apps developed on Xcode 13, which does not run on Catalina (the newest OS that the 2012 Macbook will support) I purchased a 2019 Macbook running Monterey, in which I have Xcode 13.4.1 installed.
When I run Xcode in Monterey it is much faster ( despite the slower clock rate of the 2019 machine) but a number of bugs have appeared. The major one is that a toolbar created in Interface Builder on Xcode 12.3 is not correctly formatted in an application built from Xcode 13.4.1, even though it appears OK in design mode. This bug was fixed by re-creating the toolbar in Xcode 13.4.1. When running in Xcode 13.4.1, Menu options sometimes do not appear at all and if they do appear, they only show when the touchpad is pressed and held down - they disappear if it stops being pressed. This applies to the Apple menu items as well. If the app is closed in Xcode, the Apple menu items appear normally. Other apps have their menus appearing and responding normally. If a toolbar item is clicked to show an NSPanel (via [ setIsVisible:true]; in this state, the NSPanel may not be shown and cannot be closed by clicking the red dot at the top LH corner. If the app is in the state where menus are not shown when the touchpad is clicked, adding a breakpoint in an action and resuming execution with ctrl-cmd-Y sometimes changes the app state so that menu items are shown as expected. Restarting Xcode does not change the app state, and nor does restarting the Mac or cleaning the build folder.