The Syncing with FYI message takes a long time or it does not complete the sync.
This could be caused if you are trying to sync a very large document, a very large number of documents or if other members of the team are also syncing using the same, shared OneDrive.
If OneDrive cannot finish syncing documents, this can cause issues for FYI.
Please refer to the following articles from Microsoft:
If the file is still open, FYI displays the message "Document is open and can not be synced". Close the relevant document and the sync will refresh automatically. Refer to Opening, Editing and Finish Editing Documents.