I have noticed a change since the New Year with our company Concur as well as it relates to Marriott. Now all Marriotts seem to show up as a potential violation of our policy. Here's a prime example - Marriott CVG airport, i was just there this week. It's a corporate preferred property, the rate is $2 over/under the Doubletree CVG, but the Marriott comes up as a potential violation.
I actually think there is something within Concur that went quirky with Marriott with the start of the New Year.
I'm still able to book Marriotts, however I have to explain my justification in the system and sometimes it's a little difficult where there is a Hilton down the street that's the same price and doesn't throw up a violation flag.