ht800 with dtmf front

[mrpurrfect69]

Hi just after abit of info,
I have 6 of these ht800's with the dtmf front keypad...I have ran the rss & it seems to read the code plug but it says UHF CROSSBAND TX 440-470 & RX 420-435ish.......When i try to set a new bandsplit & program the radio to new frequencies the radio just won't accept it at all, I've managed to change the codeplug to around the 420mhz & it recieves ok but when i go to transmit it just beeps when i pree the ptt any ideas how this is.......& can anyone advice me on what steps to take to get the radio's working back to back?
Thanks In advance