Can't assign address to igc

From: Chuck Tuffli <chuck_at_freebsd.org>
Date: Tue, 01 Aug 2023 17:46:49 UTC
Running a recent-ish version (n264266-8f8da1bcc799) on an Intel NUC
(RNUC11PABi5), assigning an IPv4 address to igc0 doesn't work. There
is no error message, and this has been working in the past. Looking
through dmesg only shows:

igc0: link state changed to UP
igc0: link state changed to DOWN
igc0: link state changed to UP

The address is set in rc.conf:
ifconfig_igc0="inet 192.168.5.10 netmask 255.255.255.0"

And manually setting it via
# ifconfig igc0 inet 192.168.5.10/24 up
does not work either. Any suggestions?

--chuck