MSO Files being randomly renamed while open on desktop

Hi, a random number filename usually points to a save/sync conflict, temporary Office file behavior, or an issue between Office and OneDrive/SharePoint sync. I would first make sure Office is fully updated, then test with AutoSave off and with the file stored in a plain local folder outside OneDrive. Also check OneDrive sync errors and file locks. If it only happens in synced locations, pause sync before opening the file and see if the problem stops.