The first thing to check when you have interference is what transmission system you are using. With 2.4GHz video system, you must use 900mhz or 433mhz control link. You cannot use any type of 2.4GHz control link as it will cause issues.

Ensure that you use channels that do not overlap bluetooth or wifi bands, which can vary from country to country. Bluetooth operates at 2400-2483.5MHz.