Missing/unmounted media libraries within Apple Media Services dependent apps (Music/TV/Books)

I had this in another post as a reply to a comment - but figured this should become its own topic in the event others are experiencing the same issue. Note that as of this writing, there is still no solution.

To summarize - several weeks ago, I signed out from Media Services (within iPadOS's TV app) on a Mini 5. When signing back in, my media library (in the sidebar) failed to mount - i.e. no items under the "Library" dropdown displaying (and categorizing) all of the cloud purchases. Already aware that at times the mounting of the media library could take several days (depending on the size/number of purchases) to rebuild and reappear in the various dependent apps (TV, Music, Books), the libraries still failed to mount after 3 weeks.

The following were all attempted, with no successful results:

• • Updating to latest iPadOS (this was done again the other day, from 15.5 to 15.6)
  • Sign out/in from iCloud and/or Media Services
  • Deleting TV/Music/Books apps from device and reinstalling from App Store
  • Restart/reset of device
  • Erase and restore from backup
  • Clean erase and restore (set up as new device)

I actually went out and purchased the iPad Mini 6 the other night, wondering if this issue was due to some faulty hardware inside the Mini 5. Took the 6 out of the box, signed in with my Apple ID, and....... libraries fail to mount once again.

Here is a side by side of what I see - the first image shows all of my true recent purchases from the iTunes Store, which one would expect to see under "Recent Purchases" in the Library (if operating correctly). The second one shows the TV app featuring only a single manually downloaded (from iTunes Store) title (i.e. it becomes the only "Recently Purchased" title):

Note that the TV app isn't the only app affected - the Music cloud library fails to mount, as well as purchased audiobooks from within Books.

The only item where cloud purchases are being recognized as per usual is the e-book titles from within Books.

All other audiovisual media (music, movies, tv shows, audiobooks) seem to fall under the auspices of Apple Media Services - if the respective apps in question all have some dependencies on Apple Media Services, perhaps this is where the disconnect is occurring.

Interestingly, the time to "login" to Apple Media Services (from Settings) - i.e. the duration from just after entering password to the point where the login wheel disappears - seems to be faster compared to several months ago, about 1-1.5 seconds versus about 4 to 5 seconds. Sometimes, faster isn't necessarily better, as it could indicate some unknown connection failure occurring here.

This is what I'm referring to:

The fact that this issue occurred on more than one device (the latter literally being right out of the box) leads me to believe that it is not a hardware issue, not a software issue, but moreso an issue with the device establishing the proper connection to Apple Media Services using one's Apple ID.

Furthermore, it is important to note that I - along with some other posts I came across having the similar issue - have a large purchased media library. (the purchased movies alone, if all were downloaded in HD format, would amount to over 2 TB according to Monterey's TV app status bar)

Is it possible that Media Services is rejecting connections from Apple IDs whose overall library size exceeds some maximum? Unfortunately, there is no connection log to follow with this screen (to indicate rejections, timeouts, etc.) but if there is, I'm suspecting that iPadOS may think that the connection has been made when in reality it hasn't.

Everything else on my Apple ID was intact - no blocks or flags, according to the iCloud specialist I spoke with. All purchases (from my iPhone) still going through as per usual, and appropriately appearing in the correct apps' libraries on my iPhone (iOS 15.6).

I have an open ticket with Support on this (currently working with Engineering) - expected a call back the other night, but did not get it as of yet.

And up to this point in time, nobody I had discussed with - sales people at Apple Store, Genius Bar staff, telephone support staff - has heard of this issue occurring.

If this issue remains unresolved, although there are "workarounds" to retrieving some media to the device (i.e. manual downloads through the iTunes Store), it nonetheless creates a huge dent in the quality of the user experience of these media apps. I am highly apprehensive in signing out/in from my iPhone, as this is the last device I have currently working as expected.

Wanted to get this out there to the Community, to see if others may have had a similar unfortunate experience with truly missing libraries. As I said, I am still waiting for a return call from the tech support specialist assigned to this.

Also - I've logged several feedbacks about this issue already. Hopefully at some point it will reach Engineering's radar...

Thanks all

[Edited by Moderator]