RE: 2.4 ghz interference: It can happen!
There are many reasons 2.4 CAN fail. How are the batteries? What kind and what capacity?
Are you running thru a regulator?
Are you using heavy duty wires thru the switch? What are your switches?
How is your receiver orientated in your aircraft?
Are you flying in the vicinity of a large mass of metal that could cause reflections?
What is the sun spot activity? A large flare can wipe out communications.
I am sure there are more. Its tempting to blame the radio.
2.4 was developed with spread spectrum technology to be highly resistant to any kind of interference but there are plenty of other ways it can fail