DSM2/DSMX issues AR8000 receiver

Greetings

I have a weird issue with an Spektrum AR8000 receiver (not genuine, a Chinese copy)

Will bind and work perfectly with Spektrum DX6 transmitter using DSMX or DSM2 with no range problems

Will bind and work on Devo 10 using DSM2 with good range but ONLY if I select 6 channels any more than 6 and just won't bind

Will bind and work on Devo 10 using DSMX with all 8 channels but range only about 2 metres before starts browning out. Situation gets better with fewer channels but still not great.

I have scoured the forums and found numerous posts on DSM issues which is where I got the idea to play with the number of channels.

Any ideas as to why I am seeing this behaviour.

So I got a genuine Spektrum AR8000 and that works perfectly with my Devo 10. Strange that the other one worked fine with the DX6 though but nonetheless, clearly a receiver issue. Moral of the story, the only Spektrum clones worth buying maybe the Orange ones from HobbyKing. I have never had any issues with those.