New TCL TV pairing with XR15 remote, but now no other functions work - HELP!

We just got a new TCL Model 55S450F Fire TV. Today, after more research than I expected, I programmed our XR15 remote to the new TCL TV which let's us control the power, volume and mute buttons. However, I now have no other functions available on the XR15. No channel guide, no directional buttons, no Xfinity button. Nothing except volume, mute and power for the TCL TV. Please help!

Tony in Virginia