Retevis RA685 - using with other radios

Hi, newbie here. I have several two- way radios that are PMR446 type and they all work with each other fine. I have just purchased a Retevis RA685 but am having problems getting it to talk to one of the others. At the moment i have the others on ch2 and ctcss 2. I can talk to the Retevis but can’t talk to the others from the Retevis.
The manual states that when broadcasting it will show a red LED but this only happens if i use it in channel mode. In channel mode it doesn’t receive from the other radio.


Anyone help me on this?
Thank you.