Thanks. GANPKRF is the unit with the problem.
I understand this is a tmp file. But it seems to have no connection with a file on this or either of the other two units. All have a good copy of GROCERIES. There are no conflicted copies on any unit. Which is why I am coming here for help!
The doc your recommended states:
the temporary file is kept around for up to a day.
but this has been there for over a week.
Under failed items it says:
The following items could not be synchronized. They are retried automatically and will be synced when the error is resolved.
GROCERIES.sync-conflict-20230611-113322-GANPKRF no connected device has the required version of this file