When using the When File is Created Trigger on a SharePoint Document Library, frequently my flows have to update a column on the triggering file. SharePoint Online file locking is a bit laggy in that the file will be closed, but SharePoint Online hasn't released the lock yet.
As a work around I ofter put a pause into the flow, which is ok, but not perfect. Better would be to have a Flow Step "Pause until File Unlocked"