GCPro Box UART Port Not working

Hi team:

Using Version…
Selected Port VCP0 = COM5
Selected Model GT-I5503

Searching phone…

No reply on samsung mode.. DIAL *#0*# AND TRY AGAIN…

Phone Not Found Retry Please.
Total Time Take…00:00:12

I been using this box for the past month, UART port works fine. But last few days i noticed that i did not work anymore.

I have to use another BOX’s UART port to fix my phones. (Octoplus Box)

Both Com Ports use the same driver.
Driver Provider: FTDI
Driver Date: 1/6/2016
Driver Version:

did my box’s UART actualy failed/broke? is that common? or could be some settings, or configuration?

If it could be configuration, could anyon e point me to the direction where I should look?

Thanks a million!