timeout setting parameter via xbee_cmd_send

I want to setup the “SP” parameter at runtime in my XBee-Pro Module. (At startup i want to set a short SP paramter, after a setup time of 5 minutes i want to set a large SP parameer to save battery)

When performing the command at startup, everything is working. The associated xbee_cmd_callback confirms the success of the command with the flags.

But when i set this parameter after 5 minutes of runtime, the callback shows the flags with the XBEE_CMD_RESP_FLAG_TIMEOUT bit set. The command is NOT working as expected.
Retrying the command does not lead to success for sure, most of the time it workes after 5-10 repetitions.
I tested out the possible delay time: 2 secs after startup works, 4 secs after startup does NOT work.

Am i missing something to “wake” (?) the device before sending the command after some runtime ?

Try monitoring CTS flow control to know when the radio is awake and then issue the command.

Monitoring the CTS line does not work.
CTS is always 1.