I use ch 2 and 5. You have to go in and inhibit the gear channel and then mix the gear channel 100% to the elev. The channels you are using should not be the problem this is just how I do mine. The RX when it recieves the signal sends the impulses to the servos in order. First 1 then 2 and so on. I may only be a fraction of a second difference but 2 & 5 are closer than 2 & 8. Sorry to ramble back to your problem. I would suspect there is a wrong setting on your mix screen. Look and see if the link& trim is on or off. Try changing one thing at a time on that screen to see if it fixes the problem. Maybe somebody else is at home with their radio in front of them and can talk you through it.

David