M$ changed TV Guide providers from Zap2It to Rovi effective on July 7, 2015. As I understand it, this affects Xbox and Media Center users or users just using their guide service like myself.
M$ ought to just own up to this as at least part of the troubles they are experiencing. Instead, the public gets a version of it fluffed up by M$ marketing. Personally, I think that I am going to switch away from using their EPG service as it is often problematic. This time, it is majorly screwed up for many users.