Comment 1 for bug 2085835

By default (and as we can see in the ID_NET_LINK_FILE= property above), the name policy is controlled by NamePolicy= in /usr/lib/systemd/network/99-default.link. On Jammy, this looks like:

root@jammy:~# cat /lib/systemd/network/99-default.link
# SPDX-License-Identifier: LGPL-2.1-or-later
#
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.

[Match]
OriginalName=*

[Link]
NamePolicy=keep kernel database onboard slot path
AlternativeNamesPolicy=database onboard slot path
MACAddressPolicy=persistent

Basically, udev will try those policies in order until one matches. Based on the udev properties above, it looks like the 'path' policy was selected. This *might* different than before, or maybe something else changed on the system that then changed resulting name constructed by udev.

Can you please enable debug logs for udev (ideally on both a working and non-working system), and share them here? E.g.

$ mkdir -p /etc/systemd/system/systemd-udevd.service.d
$ cat > /etc/systemd/system/systemd-udevd.service.d/debug.conf << EOF
[Service]
Environment=SYSTEMD_LOG_LEVEL=debug
EOF

Then, reboot, and then run:

$ journalctl -u systemd-udevd.service -b > udev.log

and attach the result.