It's a program bug - "box" and "underline" menu button highlight styles worked in Studio 23, became broken in Studio 24 and are still broken in Studio 25.
I'm afraid you're stuck with the "alpha" style for now...
bowersdroneservices@gmail.com:I guess when they call on my ticket they'll just say sorry...
They'll probably ask you to uninstall and reinstall the software
A workaroud you could use if you're using text-only captions for your chapter buttons (and not using thumbnails):
HTHRichard