pins don't know where to go when pages are deleted

I'm having a problem with Pins, and I'd like to know if others have experienced similar before submitting a bug

We're reviewing a word doc.  Collaborator usually does a good job, but tends to get confused when too many pages are deleted.  Right now we deleted a section of a document and

1) have 5 pins at the bottom of the page before the deletions.  Just hanging out there pointing to nothing. (see attachment)

2) a few pins that now point to nothing - if you click on the pin from the main review, it opens the document but there is no pin to be found.

(Not sure which is worse behavior - #1 or #2)

Both highlight a basic problem that, when pages are deleted, SB not only doesn't know what do to with the pins, but there is no identifier as do when the deletion happened.   So I click on pin 77, and it doesn't know what to do; but also can't tell me that the page that contained pin 77 went away between upload 8 and upload 9.

Anyone else experience similar?

Thanks

- John Mc