The casing of our devices was made of metal, so the inside circuit will not be interfered by other wireless signals. Normally the power of the walkie-talkie is always huge which could affect the transmission if the HDMI/SDI cable shielding properties are not good. Please try to replace an HDMI/SDI cable which has a good ability of anti-interference, and keep the walkie-talkie at least 1m away from the cable.