iPhone sync - the sync session failed to start

iPhone XS, fully up to date (iOS 15.6)

M1 Mac Studio, fully up to date (macOS 12.5)

I am trying to sync from the Mac to the iPhone but it sits on Step 1 : Waiting for sync to start then always ends with "The iPhone "' could not be synced because the sync session failed to start"

I have tried on cable - I have tried a normal Lightning cable in the hub on my keyboard, in the hub on my monitor, directly in the back of the Mac. I have tried a USB-C to Lightning cable directly in the Mac.

I don't believe it is a cable issue because I can transfer e.g., photos *from* the iPhone to the Photos app with no issue - there is some other issue syncing back.

I have tried on WiFi.

I have restarted the iPhone.

I have tried adjusting/reducing what is in scope for sync (at this point it is just Music and Photos).

I have tried creating the backup manually which succeeds. Then the number of steps reduces from 6 to 5, but it's still the same issue.

At this point it seems like there is some wider issue blocking it. What else can I try?

Thanks!