Some (but not all) Xfinity boxes require an OK / Enter signal when programming channels manually for Flipper's "Favorites" function. In Flipper, the OK signal is in Flipper's Mute button.
To set Favs:
1) Press and hold STB and ADD at same time till ght solid, then release;
2) The channel format is: 1-2-3-Mute-ADD; 4-5-6-Mute-ADD; etc.
3) Exit: press and release STB once; test;
4) Dual Mode to work both devices: press and release ADD once; test;
5) LOCK: press and hold ADD till light solid, then enter 955.
Older models of Flipper (V3 and below) d not have this functionality. Only recourse is to upgrade to a current model.
Flipper does not have the OK signal when entering channels manually, outside Favs. To do this, try and use Learning to copy the OK signal into Flipper's TV Mute button. Please refer to your manual for those instructions, or online HERE