This looks related: https://github.com/NetworkConfiguration/openresolv/commit/0fdbfd03b554b82a8d5847d5fbecfa2814cf2499

(Not sure if this introduce or fix this behavior)

However, according to the commit message it looks like your resolvconf.conf miss a resolvconf=no.
Maybe with this setting, it’s work as expected.

And a second point (but not directly related to your network issue. The GitHub page of dhcpd says, it’s end of life and you should think about migration to kea. 

Von meinem iPhone gesendet

Am 29.06.2025 um 12:17 schrieb David C Rankin <drankinatty@gmail.com>:

On 6/29/25 4:37 AM, David C Rankin wrote:
  We have a winner! openresolv gets the bug. One hell of a process of elimination :)  Thanks to all for suggestions that got this identified. I'm going to bed...

Upstream bug:

openresolv 3.17.0-1 breaks netctl unit startup if resolv.conf has immutable attribute set
https://github.com/NetworkConfiguration/openresolv/issues/38


--
David C. Rankin, J.D.,P.E.