Hi Pavel
MCU-Link UART ports are detected as following when MCU-Link Pro debugger is connected to my laptop.

COM11 port in loopback mode (with J19 Purple and Grey ones UART Tx and Rx connected.

COM 19 is working in loop back as well. But for my exercise I have tried to use both COM 11/19 anyway for the NXP MCU Boot utility.

What I have noticed is I am able to use VCOM2 (COM 19) to detect the HW through the NXP MCU Boot utility tool but some how the VCOM p(COM 11) doesn't still detect the HW when I tried to use it along with the boot utility. Could you please explain this behavior ??