Neverending iOS sync on new device

Hi -- I'm using Joplin 12.7.2 on a new iPhone SE with ios 15.4.1. I have Joplin happily syncing via Dropbox to Macs, iPads, terminal apps and it also synced fine to my old iphone. However, with the new one, I get a never-ending sync status saying "Created local items: XX. Fetched items: YYYY/ZZZZ" where ZZZZ increments by 500 or so every time YYYY gets naer it, and XXX rarely updates. The app shows none of my notebooks, and two notes in "Restored Notes." My sync status lists a few items that can't be synchronized and will "remain on the device" because of oversized attachments. There are no attachments at all on the device (it's a fresh install of Joplin) and
I have set Attachment download behaviour to Manual.

My sync log has nothing but "Sync: fetchingProcssed: Processing fetched item" over and over, along with a few failures to acquire lock, and some other messages shown in the attached screen shot.

Hi @laurent any ideas on this? I have uninstalled the app several times with the same result. thanks.