XPB24C XBEE TH PRO firmware upgrade fail

We need upgrade firmware to some XBEE XPB24C devices that are soldered on our boards
We have to change the firmware from 802.15.4 version 2002 to the DigiMesh firmware

Our board use two UART ports one communicate with XBEE moduel and the other is used for PC connection.We have write a little program that create a bridge between these two uarts.
Progam also replicate RTS and CTS lines from one uart to the other.

WIth XCTU program we are able to communicate with module, read/write AT parameters.
BUT when from XCTU we start the firmware upgrade the procedure fail
Below the procedure details

  • Getting device information… [OK]
  • Entering programming mode… [OK]
  • Configuring port for bootloader… [OK]
  • Getting hardware version… [ERROR]
    Could not read the hardware version of the radio module. > Bootloader not responding.

Module lost communication to XCTU until new power cycle

Hardware version ATHV = 2D42

We can try to upgrade using radio remote command but if upgrade fail…