iCloud kit endless sync loop (and renaming too)

Hi team…

My sync for my iPhone is failing. It seems to be stuck in a loop where it starts the sync from scratch over and over. This is really grinding my data.

Last night while it was syncing (left open overnight) it got into its loop and ended up renaming the database too (database has mix of synced and indexed files and folders). I deleted the app restarted the phone and began again.

It’s still happening. This am its now just restarting its sync over and over.

The sync is via iCloud kit. I have verified the database on my iMac and it’s good. I have it synced to my iPad and it works just fine. So I can’t understand why it’s just happening this way on my iPhone?

Thanks for your ideas in advance.

Are you indexing files in a cloud-synced folder, e.g., Dropbox?

Yes. But it works flawlessly on the iPad. Just the phone…

How do the two devices compare with IOS versions, space available, etc.).

They are on the latest iOS. 14.4.1. 512Gb with 200Gb free. Now it’s stuck in the loop again even though I’m on a direct ethernet connection with 400mb/s upload and download. And it’s kicking out all these messages that there are “.manifest” files missing.

As it’s the only one of three not working, maybe the iPhone (technical term here) is “hosed” and needs re-start yet-again, or at worst a rebuild from backup. Or a hardware issue lurking?