1. According to the Marriott Lurkers in this forum (see post #220 in this thread), as confusing as it sounds, the SNA system is separate from the reservation system, so if a suite is showing as currently unavailable or available on the website, that does not necessarily mean it is currently unavailable or available for SNAs.
2. As of March 2019, there is an IT bug on Marriott's website that prevents SNAs from being applied to many if not all prepaid reservations. One member has identified a workaround that enables you to "trick" the website into allowing you apply SNAs to prepaid reservation. Several members have reported success using this workaround to apply SNAs to their prepaid reservations. Hopefully Marriott will fix this IT bug in the near future.
3. After SNAs are redeemed, they are removed from member's account. But they are in pending mode and will only be processed (confirmed or denied) about one week (normally 5 days) prior to actual stay. Any change to the reservation during this pending period may detach the SNAs. Check with reservation agent again to have SNAs re-attached again.
4. After SNAs get cleared and confirmed, they are locked with the reservation. Any further changes to the reservation may break the confirmed SNAs. It is a hazard to ask agent to process SNAs again since the SNA processing window is closing
5. If your SNA clears, be sure to take a screen shot of what suite category you are assigned in the app and be prepared to show this to the front desk at check-in. Several members have reported being confirmed in certain suite categories when there SNAs have cleared or during mobile check-in only to be assigned lower a category room at check-in. Members who have taken screenshots of their initial SNA assignments have had success in getting properties to honor those original assignments after initially getting assigned inferior rooms at check-in.
6. If you are assigned a lower category of room than any of the options offered during the SNA application process and/or if the hotel refuses honor the representations they made at any point during the SNA process, be sure to submit a formal complaint to Marriott and ask for your SNAs used during your stay to be reinstated. If you have followed the screenshot best practice, your screenshot should go a long way towards getting Marriott to eventually refund your SNA, although it may take a long time for customer service to process your request.

Not all hotels participate in Suite Night Awards. Suite Night Awards are not redeemable at the following brands (subject to change at any time; see Marriott Bonvoy Terms and Conditions for full details): The Ritz-Carlton®, Protea Hotels®, Aloft®, Element®, Design Hotels™, all-suite hotels, Marriott Executive Apartments®, Marriott Vacation Club®, EDITION®, Ritz-Carlton Reserve®, The Ritz-Carlton Destination Clubs® and Marriott Grand Residence Club properties. In addition, Suite Night Awards are not redeemable at select Participating Properties. Contact Member Support for individual hotel Suite Night Award participation.

From post # 220.

The system is not checking what is available for sale at any marriott.com web site, so you should not be using the web sites as a guide for what is and is not available for SNA approval.

Best regards,

William R. Sanders
Social Media Specialist
Marriott International

FOR ANYONE TRYING TO ADD SNAs TO PRE-PAID NONREFUNDABLE BOOKINGS THAT MARRIOTT IT
CURRENTLY DOESN’T SEEM TO ALLOW, HERE IS A WORK-AROUND. GOOD LUCK!

https://www.flyertalk.com/forum/30575978-post541.html


The link for selecting your benefit:
https://choice-benefit.marriott.com/

How to cancel an Award request:

Suite Night Award requests may be canceled until 2 p.m. local hotel time the day before you arrive, as long as the Awards have not already been confirmed for use on a reservation. Once your Awards have been confirmed, you must cancel the entire reservation to receive credit back for all the Awards; however, after 2 p.m. local hotel time the day before you arrive, a reservation cancellation will result in the forfeiture of all Suite Night Awards applied to the entire reservation. This is in addition to any other cancellation fees applicable to the reservation itself.

NOTE: Always detach the SNA before cancelling a reservation. It's the only way to ensure your SNA is returned to your account immediately. Otherwise, you could be waiting hours/days to see your SNA again.