[Ma'am-I-Am]

I don't know if this is a PW problem or a Calibre problem.
I was backing up my PW2 using a dedicated Calibre db for this. I had a number of books sideloaded and direct from Amazon, plus articles and pdocs - all sorted into various Collections over the years. My PW storage is tapped out.

Somewhere during this late night messing with Calibre & the PW, I noticed the icon to update metadata on the device, so I highlighted them all and ran the update. Here's the situation now:

Using PW, some Collections show, others don't.
Using PW, the Collections that do show don't have the right number of books.
Using K4PC, all collections on Amazon are visible and complete.
New Collections created since then using PW show as blank names on Amazon, although the number of books added to them via PW is correct.
Items added to the new collections show under that collection, but do not disappear from the main page (I use list view).
I have not tried using K4PC to view those new collections yet. I deregistered it and I have no idea why {flappingly frustrated with self}.

One extra thing that may have contributed to this: The Husband and I use a single account and he registered MY PW2 under his name ages ago. I recently changed the Amazon account email address to one of mine because I wasn't getting certain notifications, etc. When the issue with the collections happened, I changed the account email back to his. This made no difference to the collection problem, i.e. it's still f'd up.

I've been using this PW2 for years so I know about filtering, sorting, all/downloaded. I've restarted more than once, but have not reset or deregistered - I want to avoid that considering the volume I have on the device.

Am I SOL in trying to recover the Collections and their proper contents?!