sync issues between Lightroom Desktop and Classic

In Lightroom Classic 13.0.1 my sync activity is always unfinished. It affects about 30 photos though the sync details/errors aren't very descriptive. Does anyone know what the best course of action is for the statuses 'error' 'metadata'  etc. Having looked at https://lightroom.adobe.com/ I see no sync errors. The sync activity is not consistent between Lightroom Desktop, Lightroom Classic and iOS Lightroom. 

In Lightroom Classic I've tried exporting a small selection of the ones not syncing and tried reimporting them using Lightroom CC 7.0.0 and although they do import without error, the sync also doesn't complete there. The photos are from different cameras so it seems unlikely that it would be a source issue.

I contacted Adobe Support over webchat and the technician advised duplicating the catalog and seeing if the new version would sync to completion, it didn't not and actually has more incomplete sync'd photos than the original

This is on macOS 13.6.1