Stu has a point I had an issue with a mars r wheel radio on 40 mhz until it was pointed out that they only like hi response rxs also had isdues with early ko 2.4 system like stu it was shy snd didnt like binding in a room full of people
I hadvto takevit outside where it wad quiet, once bound no more problems but as your system was fine before it still looks like a sanwa gemini is the simple solution
dave