Before you try to change the SSIDS run the below command on each device. This turns off automatic merging of the two SSID's back in to one SSID after a reboot. (This is the most common issue on the latest firmware).
config set wifison-monitor_stop=1 （这步很重要！！！）
The commands below will then set the the 2.4Ghz and 5Ghz networks to the names you want:
config set wl_ssid="YOUR SSID 2.4Ghz NAME"
config set wla_ssid="xx_5G"
Only reboot the RBR50.
Switch the satellite RBS50 off once you have issued the command and don't bring it back online until the RBR50 has fully rebooted and settled and you can see both SSIDS's. Once the RBR50 is back on line and both SSID's are availabel switch onthe sattelite RBS50 and let it settle. It will also begin advertising the new SSID's。