If you refer to my post 71987 on the 5th December and watch my video. I would think it likely that it is a hardware issue.
I have tried contacting the seller, and Jumper TX direct by email a number of times.
I did not get any replies.
In the end I contacted Jumper Radio via the Facebook page and have had personnal emails from him stating that he would help resolve it, but that was 11 days ago, and still no response.
Cheers
Suter