I believe the issue is the shorter stay usually processed before the longer stays end.
For example 1st and longer stay : 1-20Nov
and 2nd and shorter stay are : 7-9 Nov

on 9Nov the system process the point n nights
then on 20Nov they recognise that there is an overlap reservation and reject the longer stay.

And for multiple room points, I usually booked them in 1 reservation or combine them when check in and put the entire charge on my personal room folio.
No issue so far with points earning.

It is, of course, a PITA but you can get this fixed if you kept your documentation and contact customer service. You shouldn't have to, but you do and if you persist then somebody will fix it for you eventually. I don't get too make incorrect posts but when they occur then I email the case with my folios and an description of what I expected to happen and eventually they reply and fix it.

I have a similar issue coming up. I have a 7 night stay starting next week and ending after Jan 1. Depending on stays between now and then, I may find myself one night short of Titanium. If that's the case, I'd like to do a 1 night stay at another hotel in the midst of my 7 night stay. Based on what I've read, should I expect:

-The 1 night stay will post, because it is the first check-out day.
-The 7 night stay will not post, because the system will reject it after check-out because it sees a one night overlap.
-I can reach out to Marriott to rectify, will they credit me for 6 nights of the 7 night stay for 2021?? Or something else?

.

You cannot earn extra elite nights for concurrent nights at different hotels, so why would you do this to try and earn Titanium? Just make your seven night stay a night longer, if you need an extra night to hit Titanium, assuming the eight nights would all fall within 2020.

I'm not asking to earn extra elite nights. The 7 night stay does not count towards titanium because it ends on Jan 2.

The days of the 7 night stay that occur in 2020 will count toward 2020 EQN, eg through 12/31/2020.

If you need one additional night you will need it before your 7 night stay begins.

You can’t be in two properties at once to get nights.

If you need 7 nights to hit Titanium you need to do a night elsewhere before your 7 night stay starts. (6 nights are 2020, 1 night is 2021)

Got it, for some reason I thought any nights in a reservation that ends in 2021 count towards 2021 elite qualifying. I think maybe Hyatt does it that way and in my head just assumed it was the same. As long at the first 6 nights count towards 2020, I won't need any additional nights. Thanks all!

Hi, I had a 5 night stay from Nov 13-18 in one Marriott hotel and then had to travel for one night on Nov 14 in another Marriott hotel. Only the 1 night posted for nights and points. When I emailed customer service to get the 5 night to post instead they are telling me I won’t get the night OR the points for the 1 night stay. I understand not getting the elite night credit but I thought you still can get the points for up to 3 rooms per night? Does it matter that they are two separate hotels? Is the customer service rep correct here?