TV CBS vs FOX

[LPMAN]

For a long time Sunday day games have been on CBS when its two AFC teams and FOX when it's two NFC teams, and when it's one of each the visiting teams network.
This weekend is totally different, anyone know why?

BILLS AT DOLPHINS is on FOX instead of CBS
BENGALS AT BEARS is on FOX instead of CBS
COWBOYS AT CHARGERS is on CBS instead of FOX

rest of the games look like the normal "formula".

[T.Ferguson]

I think this actually happened last season as well, I believe it's just part of their new TV deal with the league. Before it was NFC road team vs. AFC team would be on FOX and AFC road team vs. NFC team would be CBS but now it's certain AFC games are Fox and vice versa.