Raspi 4 failing to make usb connection to MCU

Hello everybody,
I’m running into thre same problem.
I tried using the commands into Debian Bullseye Bug causing Klipper to no longer find the printer board but the commands give me no positive feedback I think:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 0E98404D386FA1D9
Warning: apt-key is deprecated. Manage keyring files in trusted.gpg.d instead (see apt-key(8)).
Executing: /tmp/apt-key-gpghome.NhhImxKvYW/gpg.1.sh --keyserver keyserver.ubuntu.com --recv-keys 0E98404D386FA1D9

same thing for the other command.
What should I do? What files do you need (logs, cfg, …)?
Thanks in advance for your attention.