Scribbles for my bad memory

This is because Debian 11/Debian 12 with Gnome does not ship with the packages to display tray icons. To install and enable the correct packages to display tray icons, run the following command:

sudo apt install gnome-shell-extension-appindicator

Then either reboot or log out and back in to Gnome, and run the following command:

gnome-extensions enable [email protected]

Reference

answer:

1. Edit the file /etc/systemd/system/multi-user.target.wants/tailscaled.service,
2. Add the line "LogLevelMax=3" in the [Service] section.
3. systemctl daemon-reload
4. systemctl restart tailscaled

Reference

In short,

sudo vim /etc/systemd/logind.conf

Find and uncomment the following lines, and change the values

HandleLidSwitch=lock
HandleLidSwitchExternalPower=lock
HandleLidSwitchDocked=ignore

Save and exit, and 

sudo systemctl restart systemd-logind