Okay, some really bizarre ideas:

1. The new KStars is picking up the wrong .xml file for the UI from some other folder

2. There is some user-customizability in the menus (I see none of your menus match!), that causes a modified .xml file to be stored somewhere in the user's setting list. This is not overwritten / the new menu items are not added to this when a new version of KStars drops. (Possible, although I don't know of any menu customization in KStars; that being said even some of us developers hardly know 20% of the features)

3. It has something to do with the theme: dark mode vs. light mode. (Very unlikely)

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