HI @katsu,
sorry for the confusion. I can see the output on UART_2 because I am using the modified code from this other thread.
This is an evolving topic so our information keeps getting updated.
Also, as far as I have tested as of today, debugging is allowed with a cable connected to X18 as long as you first start the debugger without it, and connect it afterwards.
It is indeed a very strange behaviour on a topic with not much information, but we are investigating it at the main office right now. As always, I will keep updating with test results and any new information we might have.