This HowTo is aimed at people who use the default LTS kernel provided by Linux Mint LMDE. (Currently 6.1.0-29)

In my case after updating, the firmware of my network card went from the RTL8168 supplied by default to the RTL8125 firmware which is adapted to my network card.

Get the latest firmware, in a terminal as root:

apt install git -y

cd /tmp

git clone git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git

cd linux-firmware/

cp -va * /lib/firmware/

You need to update the initramfs to compile the firmware with the kernel:

update-initramfs -u

Reboot to take effects:

reboot

Enjoy!

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