XBee S6B WiFi AT DB Command for RSSI

I’m running the AT “DB” Command for RSSI of the Access Point for a XBee S6B in Client Mode.

The command I run is:
char ACCESS_POINT_SIGNAL_QUALITY[] = { 0x7E , 0x00 , 0x04 , 0x08 , 0x01 , 0x44 , 0x42 , 0x70 };

This matches X-CTU’s Frames Generator:
7E 00 04 08 01 44 42 70

I successfully run quite a few other AT commands with the same code interface but the DB command always gives me a 0x02 status or “Invalid Command”.

When I run the command, the XBee is connected to my router and can send and receive TCP packets.

What is happening here? Why do I get Invalid Command for this particular AT commad?

PS I updated to the latest Firmware and still get ‘Invalid Command’.