My experience today...
Called Marriott Reservations number on the back of my card
After reserving, the rep said she had to call MR to attach the certificate (yes, they were open, at least for this).
After probably 45 minutes between the Marriott and Marriott Rewards reps, they first took points out of my account, instead of attaching the cert. I finally have a confirmation and show the correct number of MR points, but the cert still shows in my acct.
They are really swamped and it sounds like new systems and cross training are to blame.
I will follow this reservation until I’m sure all is ok. Cheers.