I purchased one of the UV-5R GMRS radios from Amazon. It was from the Amazon store that came up when clicking on notarubicon's affiliate link. It would not transmit on Ch 15, nor 462.550 programmed into one of the higher channels (while trying to transmit in channel mode). They won't transmit in frequency mode, at least according to notarubicon, and that seemed to be the case with that first radio. It WOULD transmit on both Ch 15 or a higher channel if I programmed the channel to any frequency 462.560 or higher. All programming on it was done on the face of the radio.
I ended up sending it back for exchange. Second one was the exact same way. In the meantime, I had ordered a programming cord, and downloaded CHIRP. I attached the radio to the computer (a MacBook, but I was using the compatible CHIRP, so I think it should have worked?). I could not get CHIRP to talk to the radio. Tried numerous times, no joy. So, I sent that second radio back to Amazon as well, for a full refund. I've given up on the UV-5R GMRS, as it seems that everywhere it is available lately, it is disabled for Tx below 462.560. And yes, I know that 462.560 isn't a GMRS frequency. But it would Tx on that frequency, when programmed into any channel, and operated in channel mode.