nRF5340 PDK: Bluetooth Central UART example doesn't work after replugging USB cable

[RAlexeev]

When I compiled your sample Bluetooth: Central UART from both master and v1.3-branch branches for nRF5340 PDK (network core has Bluetooth: HCI RPMsg firmware) and I use a serial monitor to see UART output from /dev/ttyACM2 port, then everything operates properly. I can push button BOOT/RESET and see logs in a serial monitor. But everything works until I unplug USB cable with nRF5340 PDK from a computer. When I plug it again I already see nothing in the serial monitor, even after pushing BOOT/RESET button. I don't see even such string *** Booting Zephyr OS build v2.3.0-rc1-ncs1  ***. Even when I built it again from SEGGER Embedded Studio for ARM Release 4.52 (Build 2020033100.41808 Linux x64) and run I saw nothing in the serial monitor. And to force it to work I had to build and run another example. Otherwise /dev/ttyACM2 port was completely silent, even after rebooting a system.
However, when I use the same example Bluetooth: Central UART with nRF52840 DK, then I can unplug and plug the development board as many as I want and UART output works properly, unlike nRF5340 PDK, which outputs nothing to /dev/ttyACM2 port after one time unplugging USB cable.

[Didrik Rokhaug]

Hi.

You might have to re-open the virtual port when the device has been disconnected.

Best regards,

Didrik

[RAlexeev]

Thanks for your response, Didrik. As I wrote, I even rebooted a system, and, certainly, I reopened a serial monitor. It hadn't helped.

[Didrik Rokhaug]

Hi, and sorry for the late answer, but we have been a bit swamped during the summer vacation period.

However, most of us are now back at work, so it should be better going forward.

I assume this is in one of your Kubuntu VMs?

Have you been able to reproduce it on other systems/computers?

Do you see the same behavior in other samples, or is it limited to just the Central UART sample?

Best regards,

Didrik