Syncing issues with OneDrive shared folders

There is a message elsewhere from a Microsoft insider explaining that this problem has been caused by Microsoft migrating user data. Shared folders do not work if they are in a different location from the user they are being shared with. As the migration gradually completes, shared folders become available again. There seems to be no solution except waiting for the process to complete for your own and shared folders. This explains why different users are affected at different times and why problem resolution seems random. It's a plausible explanation, but it's still annoying.

When will the migration be complete as the shared folders are for a family members power of attorney which now cannot be safely used?

I've figured out a solution to this problem, it's a little hacky but it works. Steps:

1. Click on the link from the original "User A has shared a OneDrive folder with you" email you received, and open a document in that folder in the Desktop Office App (e.g. Word). From the OneDrive website, you can do this by clicking on the three dots next to the file in the browser window, and selecting Open->Open In App[If you have 2FA turned on, follow steps 2 and 3, otherwise skip to step 4]
2. In a browser where you're logged into your Microsooft account, visit https://account.live.com/APHelp
3. Click Create Password to create an app-specific password. You'll need this in step 7 instead of your usual Microsoft account password.
4. From the File->Recent view of files in the Office app, right click on the file you just opened and select Copy path to clipboard.
5. From Windows Explorer, right-click on This PC and click Add Network Location and then Choose a Custom Network Location. You can also Map a Network Drive if you prefer.
6. In the Internet or Network Address field, paste the path to the file above, but delete the filename, so it'll be something like: https://d.docs.live.net/CIDNUMBER/Folder where CIDNUMBER is a string of digits unique to the folder that was shared with you.
7. When prompted for credentials, use your Microsoft account and password unless you're using 2FA, in which case use the password from step 3 above.

This worked for me on 2 different PCs, one Windows 10 and one Windows 11.

Thank you SS2111, this has worked for me.

SS2111 I could KISS YOU!!!!!!!!!!!! This worked for me! I can't even tell you how much I appreciate you figuring this out!!!! Why can't Microsoft be as smart and offer this solution to people from the start? They need to hire you!

YOU ARE AWESOME!!!!

THANK YOU!