A simple killall bird command in the terminal works perfectly for me.
It is probably related to the synchronization process priority, which got so low in priority that stuck in the progress.
When you kill the process the system automatically restart it and finish the sync correctly.
A perhaps similar or related bug was reported via Apple Support, it's discussed on Apple Community here:
TLDR: Try disabling time machine back ups.
After dealing with this problem for a very long time, I had given up on it. iCloud just always seemed to get stuck. I decided to try to fix it by doing a clean reinstall of the OS (Monterey). But that didn't fix it.
Finally, I noticed that the syncing with iCloud Drive did was blocked by a time machine backup process to an external hard drive. Once I disabled time machine (and ejected external hard drive for good measure), the sync started working perfectly.
I have already tried several solutions. The only thing that works to me is to create a new folder, transfer the contents from the old folder to this new one and repeat this process for all the folders above the one that presented the problem. This problem is extremely annoying. I have found reports of this bug in several foruns, but none with a definitive solution. I've tried Apple support and they couldn't find the solution.
I also experience a similar issue (macOs Monterey) when I turn off icloud drive and turn it on again the icloud drive folder keeps loading saying (intalling Icloud Drive) while nothing happens. I cant reach my folders. This doesn't solve after restarting my device. Also, when I want to turn on the yncing between desktop and documents in icloud preferences it doesnt do anything. A frequently occuring issue but can't seem to solve both.
Were you able to fix the problem? I was having the same issue. I think I found the solution though. You know how we uncheck the background and documents backup in the iCloud settings? After I checked that, it started uploading again and I was able to use in other apple devices. Try if that works...
Same problem.
In my case, I discovered there were some hidden files. After getting rid of them, everything went back to normal.
In fact, it started as a suspicion, because all the "regular" files were uploaded, so I suspected that something else should be interfering with iCloud.
I prefer to use the Terminal in such cases, so I 'cd' to the folder and there they were: two temporary hidden files left by MS Excel. I couldn't delete them using the regular "rm" command, thus I decided to go around it - I copied the files that mattered to a temporary folder, removed the folder that won't upload to iCloud (with all the hidden file on it) and then recreated it and moved the files back.
Now my folder's sync'ed and no more "Waiting to Upload".
Guys, I may have found a solution. I had the same problem Desktop and Documents didn’t sync and stuck on Waiting to Upload. I uploaded only one file through icloud.com to see what would happen and it somehow fixed everything. The files appeared on my iPhone and everything. Try it out yousrelves.
Has there been a solution for this yet? I am having this issue with one of my staff machines. I was able to copy one of the folders to her desktop, but iCloud is still "waiting to upload her remaining 2 folders" and she can only access her files through iCloud online. This started to occur 2 months ago when she upgraded to Monterey.
Very strange behavior. This happened to me from times to times. Right now, it was same but at almost the end of upload (="uploading" vs "Waiting to upload"). I tried to cancel the copy but could not. No effect on the cross. I went to Force quit to close the finder from there : Finder icon had wrong icon, from another app. I closed that app. File copy finished without doing further command.
Just like if there were some process mix. The files I tried to copy were not related to that app.
Quite strange! This problem is here for some years and no clear answer.
I am also having this problem.. I've had it on Monterey & now Ventura. I have not been able to find a solution. Restoring, Restarting Bird, Signing in and out do not resolve the problem.
I had hopes that with Ventura the problem would be solved, but it seems not. Maybe it's time to look for another app for syncing files. Too bad Apple!
Just ran into this problem again, read this thread, and felt given the wild postulated solutions here, that perhaps Occum's razor likely applies. While I have not extensively tested the hypothesis I'm about to present, given the relative simplicity of actions I took to address the issue, I feel strongly that my thesis is close to the mark.
Multi-device sync is a non-trivial exercise; there are numerous non-deterministic actions that can occur on either side of a sync session that can cause one side to "time out" or otherwise drop/pause/hang the connection and thus "hang" the process of synchronizing, leaving the other side "waiting by the sea". In my case, I had a folder with a word document and some PDFs all stuck with the "sync cloud" displayed and "waiting for upload" on the parent folder. This seemed like the classic "hang", perhaps initially caused by MS word writing to the file at the wrong instant, causing a lock contention, and thus hanging the process, and the mac waiting patiently for iCloud to re-engage, which it was never going to do.
My fix? I opened the word file, added a space character, and saved the file (yes, yes, I could have used "terminal" to "touch" the file, but this was easier). This "change" caused macOS to "restart" the sync effort, and iCloud responded, and the upload of all files was immediate and complete. Ideally, MacOS should set a state flag and sync_in_progress_duration for itself, and "time out / restart" sync efforts that have been placed in "pause" for an excessive amount of time should have the whole sync process restart. Again, not necessarily simple to fix, but my guess is there is more that can be done ala TCP/IP-like backoff and retry that would mitigate most of these hangs.
So, the thesis is "sync is hard; touching files, while annoying, is easy. Make a change, save your sync."
Hope that helps.