LFE silent..?

Greetings all,

I have many 5.1 mixes in which some appear to route fine to LFE, some don’t. The busses are the same, the LFE knob is tweaked from 0 to +10 sometimes just for testing, on both the master fader and the channel surround panner, even converting the clip to mono doesn’t do anything. The LFE channel is silent. Any ideas…??

Thanks!

-Alex