Not unheard of. I suspect it's a minimum night requirement specifically for award bookings. Some properties are notorious for doing this. No workaround that I'm aware of. Even if you book the two nights and call in the agents are unable to adjust it using the cert.

Here's a somewhat similar post on the topic from last year: https://www.flyertalk.com/forum/inte...room-type.html.

-FlyerBeek