Default notepads being odd

Just today, when I select Default Noteheads instead of my more frequently used Large Noteheads, the result is weird.
I have tried ‘Reset to Factory’, restarting Dorico and restarting the computer (iMac 2012 OS 10.15.7) to no avail. Is there something else I can re-set?

odd noteheads.dorico (509.9 KB)

I don’t seem to be able to download your project, but I bet if you go to Library > Notehead Sets you’ll find that the Default noteheads set shows a red flash on the default black notehead, showing that you’ve edited it (probably by mistake, when you tried to set up your own new set of noteheads). Click the button there to revert it to its default appearance.

Gosh, that was quick!
Yes, there was indeed a red flash (not that I remember editing it).
Thanks very much, Daniel.