error discovering device

Im trying to change my xbee from Zigbee coordinator AT to API firmware 21A7(newest) but unfortunately after updating , my XCTU could not discover the module anymore.
is it something wrong with my driver?

i am using an xbee usb adapter from funduino.
my xbee is S2
XCTU version 6.3.2

anybody can help me on this?
Thank you

Make sure your adapter has the proper connections for a serial firmware update: