I am writing down all the things related to xbee3 not recognized in xctu anymore -
XCTU cannot discover devices
If XCTU does not discover an XBee device or does not display any serial ports, try the following resolutions.
Check the configuration of your USB serial converter
On the Start menu, click Computer > System Properties > Device Manager.
Under Serial Bus controllers, double-click the first USB Serial Converter to open the USB Serial Converter dialog.
Click the Advanced tab, make sure Load VCP is selected, and click OK.
Repeat steps 2 and 3 for each USB Serial Converter listed in the Device Manager.
Double-check all cables. The USB cable should be firmly and fully attached to both the computer and the XBee development board. When attached correctly, the association LED on the adapter will be lit.
Check that the XBee module is fully seated in the XBee development board
When the XBee module is correctly installed, it should be pushed fully into the board and no air or metal should be visible between the plastic of the adapter socket and the XBee module headers. Also, double-check that all ten pins on each side of the XBee module made it into a matching hole in the socket.
Check the XBee module orientation
The angled "nose" of the XBee module should match the lines on the silk screening of the board and point away from the USB socket on the XBee development board. Basically, I have also faced this issue while working on <a href="https://www.exactlly.com/blog/index.php/mobile-erp-technology-and-its-benefits/">mobile erp</a>
Check driver installation
Drivers are installed the first time the XBee development board is plugged in. If this process is not complete or has failed, try the following steps:
Remove and re-insert the board into your computer. This may cause driver installation to re-occur.
Remove and re-insert the board into another USB port.
(Windows) Open Computer Management, find the failing device in the Device Manager section and remove it.
Download the appropriate driver. You can download drivers for all major operating systems from FTDI for manual installation.
Check if the modules are sleeping
The On/Sleep LED of the XBee development board indicates if the XBee module is awake (LED on) or asleep (LED off). When an XBee module is sleeping, XCTU cannot discover it, so press the Commissioning button to wake it up for 30 seconds.
Hope this article helps everybody.