It now seems this issue is across brands across geographic locations - a version of the system used by hotels have flaws that automatically wipe out the member number on the reservation.

It is about time the Lurkers bring this issue to the higher up / IT dept to take a serious look - since now they know which properties behave in such way, then they can identify which system these properties use, IT could zero in to identify the bugs.

Of course this might be too much to ask for Marriott to fix.