Record have not been synced or existing synced data has been invalidated

Ran into an issue where any writes to record A were failing because record B had a sync issue. Record B was the Event Type Lookup for Record A, which was why record A writes were failing. The error in our logs is below:

It sounded like the issue here: (+) Appian Community, however the difference was that our scheduled daily sync for record B passed just that same morning. No updates were made to record B, and no new data was added to record B recently enough to cause the issue. In addition, while there was a warning icon next to Sync History for record B, there was no history of any failed syncs, and once I manually synced, the error and issue went away. I'm not sure what happened how to go about checking what kind of invalid data popped up. Anyone ran into this before? TIA