Hi Diederik,
A few days ago, I went to
https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
and update the missing loaded modules.
Indeed, I noticed that I have another messages related to the iwlwifi
module: "kernel: iwlwifi 0000:00:14.3: firmware: failed to load
iwlwifi-so-a0-hr-b0-83.ucode (-2)".
I think the the root cause is that the current Debian packages firmware
packages are 6 months old and they need to be updated accordingly. New
Debian Linux kernel expects a specific version of the firmware or the
name of the firmware has changed.
Regards
O