I think you are referring to the CH value? If so, that cannot be changed. It's readable only.
It should be the SC that you are looking for. Generally the below should be the min to do.
PAN ID (ID). Every node should have the same value.
Scan Channels (SC). Every node should have the same value.
Channel Verification (JV). This setting should be enabled to ensure there is a coordinator in the network.
If you have a secured network, and if you don't want to loose the modules after power cycle, you can set JV=0 so that the module retain its parent and search for the parent in the specified PAN ID after power ON. In your case as said, CH value cannot be changed. It is Read-Only parameter. You can issue NR0 to reset the networking parameters. Or write the firmware again with default settings.