If I do Theming > Fonts and then click on any of the two font buttons I get a new window. If I in that window click any of the font buttons I get a dialog:
Dismissing the dialog makes it reappear again, and again, and again, and…
The only way to stop it seems to be to quit LiveCode Create Native.
Running LCC 1.0 DP1 on M1 Mac (Sonoma)