I have the exact same problem on the iPhone app with a reservation made this week directly on marriott.com via topcashback.

It will let me check in for my stay beginning tomorrow but will not give me access to the usual request for late check out and instead I've got this "Thank you for being a Titanium elite member... blah blah... you may not receive your benefits on this stay..." message.

I've initiated a chat with the hotel to confirm that my reservation is normal on their system. It appears normal on the web site.