Wanted to post an update to my original message. I have been on the phone several times with Apple
Customer Support, who after multiple tests have confirmed there is indeed a
problem – they have escalated the case to “the engineers” and said they would
be back in contact within a few days.
In the meantime, I was able to identify the saving issue on my PC is
isolated to two (of the 10 total) notes on my iCloud. The other notes save changes normally. So, I copied the contents (all text, no
attachments) to a word document and deleted the problematic notes from iCloud. Then I created new notes and copied/pasted
the contents of each to the new notes.
Some of the formatting was lost during this operation, so I spent time
to reorganize the titles, headings, subheadings, etc. back to the original look
and feel.
This action has solved the problem and changes/updates to these new notes
now save without problems. I can only
assume these notes had gotten corrupted somehow and were interfering with
communication between my PC and the Apple servers?!
Anyway, I hope this workaround is helpful to others.
Curt