I think it might be IR flooding to the satellite box. Try using an IR emitter stuck to the receiver and adjust the output gain on the MRF. Turn off the IR blaster in the CCP program.

Wide band vs narrow band RF just means the RF receiver in the MRF is listening for a narrow sliver of RF band for a signal and ignores RF noise on close adjacent frequencies. This will reject random RF noise when the gateway is open. THe wideband is more sensitive to more frequencies and prone to RF>IR failure when the gateway is open.