I see your smile, but can't stop myself:

It is, but we rely on damn hardware :lol

Restarting the display manager restarts the X server. With SysV, service YOUR_DM restart. As I said, just logging out and in does not read the new configuration values. So, the procedure shoud be: log out, restart DM, log in again.

Understood. It will be very educational. I hope the best to you . By the way, I felt in love with the old X system when I succeded doing what you are trying now. Back then (circa 1998) I didn't know the very existence of ssh.

I had this problem trying to use HDMI sound output, but when I selected analogic output (the one asked for by OP), it worked.

Your cron entry misses the user field. I made the same error in my cron entry tailor-made for acme.sh

May be you'd need the full path of certbot, you just check it out, because I'm not sure.

Maybe we couldn't get nothing from my idea, but I would run a RAM checker, such as
https://www.memtest86.com/
Sometimes odd things happen when the OS reaches some previously unused RAM areas.

I would try to override the default system audio using VLC. This program can change audio output on the fly: Audio -> audio device (or similar, my interface is not in English). I used this method successfully to track down some similar issues in the past.

K3b will do: https://apps.kde.org/k3b/
Using this tool yo can rip audio CD to many audio formats.
Flac is considered the best option: https://en.wikipedia.org/wiki/FLAC

Your USB-connected disk is recognized as /dev/sdb1. So, you can mount it typing this order as root: mount /dev/sdb1 /mnt. After that, you can access to its content through the /mnt/ directory. When finished, type as root umount /mnt, wait a bit for the prompt and unplug.

You're not . I keep using pure ALSA on all my desktop systems. So far, I don't need any layer on it. Sometimes I have to fiddle with configuration files, but everytime successfully.

I just started to read The Epic Origins of Hurling. I'm Spanish and love hurling.

After 20 years, at last I know how to fix this annoying behaviour. Thanks a lot!

There are quite a few FLAC files readly available for you to download.

You can try this: http://pedroreina.net/desarrollos/ca/ca0010.flac