What is the major difference between a WiFi and RF Module?
Sorry about the bad experience you had, that sounds frustrating and not too productive. I think it's important to have discussions like these as if you're disagreeing with a co-worker, not with an interviewer. If the interviewer disagrees in a way that's problematic, that will tell you something about the team, but if you're faced with a difference in understanding it can be useful to try and unpack it.

I know if I were faced with the question I'd have said something to the effect that: "the nRF24L01+ is proprietary and usually requires the designer produce both ends of the communication channel like a wireless keyboard and dongle, while Wifi is a standard that allows designers to build things that interact with other wifi devices." Mostly I think if you speculated responsibly and spoke coolly to your experience you probably did all-right on that part.

Either way, send a thank you message and take some notes on what you learned about the team or position in case it went better than you thought.