We have an odd issue with syncing of calendar meetings - some meetings do not appear on the users mobile device (Windows mobile & iPad)

Its only some meetings which are not being synced, the meetings involved seem to be ones they have received or have been created in their calendar by a delegated user

The only common factor I see is a warning in the meeting document saying it was created in a different time zone i.e "This entry was created in a different time zone.  The time in that time zone is: Wed 08/03/2017 13:00 GMT - 15:30 GMT"

If the effected user opens one of the missing meetings, directly in their Notes Mail client, then edits and saves the meeting, it will then get synced and appear on the mobile device. But obviously that is not a work around users want to live with

Does anyone have any ideas why these meeting documents are not being synced correctly?

Thanks in advance.