Cannot find buttons in Appium-Desktop

In my app (SwiftUI/iOS) I have a screen with a row of buttons along the bottom

I have given each button a unique accessibilityIdentifier.

In Appium-Desktop I cannot find the buttons.

In the Source pane there is quite a bit of XML, but no sign of the buttons or the menu

The SwiftUI is quite tortured, many nested elements. Is this some thing to be expected? Is there some other way to get to the buttons in the Desktop, other than using the “App Source” pane?