… tried every combination, to no avail.
I’m looking to set the FX for a channel, and then have the FX fully “muted” through the mains when the fader is down. Something simple, I’m sure - but I’ve tried every combination, to no avail.
Read the downloadable manuals.
If you are doing a channel insert this should work as wanted, if you are doing a mix->return then the mix needs to be postfade, if you are doing channel → return then it will depend on the takeoff point selected.
At the bottom of the FX screen there is a little rectangle with the word “Insert” in it. I discovered by accident that you need to tap that “Insert” to turn the effect on in the selected channel.
Yes, you do need to actually insert the FX engine 
There are too many ways to describe them all each time the question is asked, but once we know what the desired outcome is we can recommend a method and describe it…
Thanks…this forum seems a lot “smarter” than most (much appreciated).