Something to think of (although I would certainly not expect it to be an issue after so long) is that the router will have assigned that machine with an IP (assuming DHCP is being used) and it will “assume” another machine is being connected attempting to use that same IP etc. after a hard reset (no “handshake” or “handoff” being performed in such case).
At least, I’ve had issues in the past where I needed to reboot the router to bring the connection back to life.
Similar can (or at least, could) happen when e.g. switching between OSes on the same machine, in a dual- or multi-boot setup.
Note:
The above is mostly assumption on my part; I don’t have significant in-depth knowledge of this.
Edited to add:
I remember with my old routers seeing settings for how long a connection is leased for. I currently use an ISP-supplied router.
any ideas? I read the kernel.org mailing list and there was a closed issue from kernel version 5.5.7: I do not know what to do next! I have a workaround for wired ethernet, but wifi would be fine…
Have you tried resetting the firmware to the factory defaults ?
Another option is to disable wifi in the firmware - save settings - reboot - enter firmware - enable wifi - save changes - reboot - and recheck.
Never mind - you did that already.
If it were a general problem - a regression, it wouldn’t happen over a cold reset - the internet would be flooded with references - it seems local to your system.
I vaguely recall a couple of years back - one of Intel’s wifi cards had numerous issues - could that be the AX200? If yes - and none of the kernels 6.15, 6.16, 6.17 work, they all EOL by the way - now it is 6.18.
The list you provided above about firmware for iwlwifi - it appears truncated - got a longer list of firmware - you do have the linux-firmware intel package - right?
$ pamac info linux-firmware-intel
Name : linux-firmware-intel
Version : 20251125-2
Description : Firmware files for Linux - Firmware for Intel
devices
URL : https://gitlab.com/kernel-firmware/linux-firmware
Licenses : LicenseRef-WHENCE Apache-2.0 GPL-2.0-only
LicenseRef-intel
Repository : core
Installed Size : 110,8 MB
Groups : --
Depends On : linux-firmware-whence
Optional Dependencies : --
Provides : --
Replaces : --
Conflicts With : --
Packager : Mark Wagie <mark@manjaro.org>
Build Date : fre 05 dec 2025 23:48:26 CET
Validated By : MD5 Sum SHA-256 Sum Signature