My Fortec Star Lifetime Ultra would not show a signal for 11842, 22,000 Vertica

My Fortec Star would show a strong signal onlyfor some
settings but not others even tough another receiver
attached tothe same dish gets a signal.

For example: 11840: 22,000: Horizontal gets 0 signal strenth but with 11840
there is a signal strength. Another receiver attached to the same dish get
the specified signals and when the LNB power passthrough is attached to
the Fortec the signal works.

Strange???