Samsung UN40J5200 no signal from Xfinity boxes

the Xfinity boxes stop working on my Samsung UN40J5200  HDMI inputs, the TV recognize the Xfinity X1 is connected but shows "No Signal".
I already did several complete resets, try the issue on both HDMI inputs, and tried different HDMI cables (that work perfectly on other devises).

Note: I confirmed the TV HDMIs inputs are working properly with PC and other HD signals. It just ignores the Xfinity cable box

Please advise.