iCloud drive not syncing with Catalina update

My answer translated in English :

Apple support told me that it was a well known bug. Since Catalina, the problem occurs if we connect first at iCloud (with is most of the time what we do when we reinstall the OS from scratch) BEFORE Apple Music or Apple TV.

You can test that by creating a 2nd user account on your mac, then start a Mac session with this account , start Apple Music and connect yourself with your AppleID (the one that doesn't work on your 1st session). Following this process, it will work fine.

So you have 3 options:

1. Reinstall completely your OS (but you will loose everything, so you need to backup every personal document first). AND DONT CONNECT YOURSELF TO ICLOUD (you will do it later). When the system is ready, start Apple Music and connect yourself with your AppleID. Then, connect yourself to iCloud. If you've chosen to synchronize your "Desktop" and your "Documents" folder, it can be very long to recover everything (3 days for me)
2. Create a 2nd user account, then transfert every document from the 1st account to the 2nd, then delete the first user account
3. Wait for a bug fix of Catalina (coming soon so they told me...)

Same issue with the new macOS 10.15.1 installed yesterday. I thought it would fix the problem when Catalina was asking again and again to accept new terms of iCloud in order to get all new functionalities...

I tried a week long to enter my AppleID credentials then the Macbook credentials (I guess there was a sudo command behind). Nothing happened. So I decided to disconnect/reconnect to iCloud as suggested in many forums. Luckily macOs made a local copy first. But 36 hours later, still nothing. Desktop and Documents folders are still desperately empty. Even the link "iCloud Drive" on the top the left side bar of the finder shows these 2 folders with a nice cloud icon drawn in dotted line... and nothing inside (seems logical by the way)

I have a simple fix that worked for me. I called Apple support and they helped me through this. My MacBook using Catalina was not downloading any new iCloud files that I would create on other devices like my iPhone and IPad. The support person had me create a new folder named test in iCloud Drive on the MacBook and once it was created it fixed the iCloud handshake problem. I was able to see this test folder on my iPhone and IPad now and the all of the sudden all the other files I created on the iPhone in the Files app were showing up on my MacBook again. So glad this was an easy fix.

Après appel au support Apple niveau 2, le bug est connu des ingénieurs. Depuis Catalina l'erreur survient si on se connecte d'abord à icloud (ce qui est généralement le cas lors de la procedure d'installation de l'OS) AVANT Apple Music ou Apple TV. Pour le vérifier : créer un 2eme compte utilisateur le mac, se connecter sur cette nouvelle session, lancer Apple Music et se connecter avec son AppleID (le même que celui qui ne marche pas dans la 1ere session). Dans ce cas, pas de problème. Du coup, 3 solutions possibles:

1. réinstallation complète (mais on perd tout, il faut des sauvegardes des données), MAIS SANS SE CONNECTER A ICLOUD lors de l'installation. D'abord se connecter à Music/TV puis seulement après à iCloud). Si il y a synchro des dossiers Bureau et Documents, ca peut être long à redescendre...
2. Création d'un 2eme compte utilisateur puis transfert de toutes les données sur ce 2eme utilisateur. Puis suppression du 1er compte.
3. Attente d'une correction de l'OS (prévue prochainement m'a-t-on dit)

Werthy's answer worked for me in seconds after waiting nearly 24 hours. @Werthy, thanks for the tip! Here's what I did...

1. Create new folder called "test" in iCloud Drive on the non-syncing MacBook pro (2015 13inch retina).
2. Opened Files on my iPhone and searched for the file. (It wasn't there.)
3. While searching for the file on my phone for a few minutes, voila, my Mac Book Pro instantly populated with all of my iCloud files.
4. Yay! I celebrated! This was really worrying and ******* me off this last nearly 24 hours! Yay catharsis!
5. I also noticed that my desktop instantly populated, too. Yay, it's all synching again.
6. I came to write this response/answer, which I never do. Hope this is helpful.

Thanks again Werthy! That's the answer that nearly instantly worked for me! Woot woot!

I'm curious if syncing is still very slow on your iCloud Drive. If I update a file on my iCloud Drive from my MacBook, then go to my iMac, the file hasn't synced with the iMac . It can take over 24 hours before those files fully sync on my iMac. If I edit the file before it has synced, then I lose all the edits I previously made and an older version is saved over the new one. This is causing big problems for me.

Same problem here. Got all my work in the Documents folder on my Mac Pro, they show up in the Cloud but my MacBook Air doesn't sync anything. Logged out and in again, disabled and enabled iCloud Drive etc. and let it sit overnight, still nothing.

My own issues started a few weeks ago. Before that, never had a problem. Likely it started around update to 10.15.2.

I don't have issues with iOS/iPadOS devices, etc. However MacBook Pro, iMac will not play nice with iCloud drive. Sync will not happen, or will take a long time. Files are not synchronized even after 12-24 hr wait. I saw for first time a newly created folder (placed into root directory of iCloud drive) with a cloud-with--slash (ineligible). Never saw this before.

I have killed the bird process on numerous occasions.

Moreover, I turn on/off iCloud, delete the local directory map tried:

cd ~/Library/Application\ Support

rm -rf CloudDocs

These drastic measures help, but within about 1-2 hours, the problem resumes. Very frustrating.

I still have issues too but found a quick workaround. I go to the cloud folder where my files aren’t syncing and create a new folder. As soon as the new folder is created then all my files come downloading from iCloud.

No there’s no respond from apple and I contacted apple support department and they told me that they don’t believe there are any issue like that!!! They feels me that I am the only one who has this problem!!!

An Apple support tech took all kinds of info from my computer nearly two months ago, and I've heard nothing back since. I tried contacting the person who originally took all the info by email but I never get a reply. They're just ignoring me now. Apple definitely knows lots of people are having this problem, but as usual they won't acknowledge anything.

Typical Apple behaviour. Deny, deny, deny.

My MBP does not sync properly. Some things go through, others do not. Constantly killing the bird process but this hardly helps.

I have never had a good experience with Apple support unless it is hardware related. If they can’t fix it in 5 mins, they put you on indefinite hold. No accountability whatsoever. Perhaps this is endemic of tech support in general, but given the premium we are asked to pay for Apple products this is not acceptable.

Same iCloud Drive won't sync problem with my MacBook Pro 13" Touch Bar. I can drag folders/files from my Desktop to iCloud.com, and those sync, but no changes made on my Mac sync to iCloud (Drive.) I really think this is an iCloud issue. I'm not taking any drastic steps to try and solve it, or waste a lot of time troubleshooting something that I'm almost certain I can't fix.

WARNING. Whatever you do, DO NOT sign out of iCloud on your Mac. That causes HUGE problems and days of work to get back to where you were.