Photos not updating to/from iCloud

Oh no, I'm sorry; I didn't change that selection. My apologies.

I'm using High Sierra, 10.13.5 and Photos 3.0 on the Mac and whatever the latest iOS update is on the phone.

The Library Status on the Mac is stuck on "Downloading 9 originals" and has been for a few days now.

The iCloud settings on the Mac in System Preferences for Photos have all three options checked; iCloud Photo Library, My Photo Stream and iCloud Photo Sharing.

The Photos Preferences on the Mac has all the options checked, and "Download Originals to this Mac" selected.

The iCloud settings on the phone have iCloud Photo Library, Upload to my photo stream both turned on and the "Optimize iPhone Storage" option checked

Thanks Eric. I'd tried that already, and when I turn the iCloud Library back on it spends two days reconciling the 30K photos I have but the "endlessly downloading" the last few.

My thought is the there is _something_ about some of my files that is causing it to hang like this, but Photos refuses to tell me which ones they are... :-)

Thank you Eric. I created a new Smart Album and put some photos into it, but that didn't re-trigger a sync.

If I put photos into a Shared Album it does appear in the Shared Albums on all of the subscribed devices (iPhones and iPads), which is odd. But if I take a photo with the phone it appears in the iCloud Photos library if I access via Safari but not in Photos on the Mac. Similarly, if I import a random photo into Photos on the Mac it "hangs" on "Uploading X Items" status.

Thank you again Eric. I rebooted in Safe Mode and the same behavior persists; Photos is still stuck with the Library status "Downloading 9 photos".

If I put a new photo in the Library on the Mac or take a new photo with the phone, then Reboot the Mac those new items will sync, but the "9 Photos" problem persists.

I also did a Photos Library repair on the Mac which triggered a re-sync, and that also had no impact.

It's frustrating that there are no additional diagnostic that would tell me WHICH files are pending download, so I could to into iCloud Photos and look at them.

But, I appreciate any suggestions...

Thanks!

Thanks Eric. I re-created the Smart Album with the above condition. I also went to System Preferences and un-cheked Photos in the iCloud screen.

There was a warning that there were still sync in progress and I proceeded; it said that 9 low-resolution photos would be removed from the Mac. Probably the same 9 that it's been struggling to download; is there a way to see which those are, then I can find them in iCloud and fix or delete them...?

I re-checked Photos in the iCloud System Preferences pane, and the Library Status is currently showing it uploading my entire library of ~30k photos. Based on the last time I tried to fix this by signing out/back in to iCloud, this will take a day or two, and I'll be back to update with the result.

Thank you Eric; after three days of re-syncing the libraries, then problem seems to have disappeared. During the re-sync there were indeed 9 photos in the "unable to upload" Smart Album, but once the sync finished they were gone, which I guess indicates that the libraries (on the Mac and in the Cloud) were able to reconcile?

I tested the functionality both ways; importing an image into the Mac library and taking a photo with my iPhone, and in both cases the sync worked as expected; the images went up to the iCloud library , then were visible on all connected devices including the Mac.

Thank you very much for your patient assistance!