I have a vast number of highlights and emphasis mark-ups.
A problem is that there are few markings that cannot be deleted ("undeletable markings") on the Mac using the ERASE clickable command.
Typically it takes sometimes a minute or so for all the markings to appear (perhaps because I have so many markings), however, these undeletable markings appear immediately on boot up of the software.
Those undeletable markings are synced between my various Mac computers, and I cannot delete them on any of the Macs.
I note that these undeletable markings are not synced to iPad iOS app, so I cannot use iOS to delete them either.
Any suggestions how I can delete these undeletable markings?