Jumper T8SG rates. Help Please

I have just received a Jumper T8SG Tx running t8sg-5.0.0-7bfe9a3 FW and am attempting to set up rates using switch C. I have watched a youtube video for instruction, seemed streight forward. I set mixer/EXPO&DR but after selecting switch C0 the stick position indicator moves to the extream right as if it had added a value from the switch rather than making a decision on its position. I am new to forums I am sorry if this is not the right place for this question.