Latest managedsoftwareupdate failing on i7 macOS 13.1; appears to forget URL of munki server, reverting to http://munki/repo

[Frank Seesink]

I've noticed something odd with one of my systems.  It's a 2018 iMac i7 running macOS 13.1 with Munki tools v6.0.1.4523 installed.

Specifically, when running the Managed Software Update client, I notice it coming back with no updates, when I know for sure that updates exist (since I just updated the Munki repo).  And when I run Terminal and check, here's what I see:

____

% sudo managedsoftwareupdate
Password:
Managed Software Update Tool
Copyright 2010-2022 The Munki Project
https://github.com/munki/munki

Starting...
WARNING: Client is configured to use the default repo, which is insecure. Client could be trivially compromised when off your organization's network. Consider using a non-default URL, and preferably an https:// URL.
    Looking for local Munki repo server...
    Auto-detected Munki repo at http://munki/repo
Checking for available updates...
ERROR: Could not retrieve managed install primary manifest.: (-1003, 'A server with the specified hostname could not be found.')
Finishing...
    Performing postflight tasks...
Done.
____

Mind you, I have my Munki site at an HTTPS URL, and if I check

/Library/Preferences/ManagedInstalls.plist

it shows properly there.

Now, if I reboot the iMac, it then seems to update once again.  But only for a short time.  Eventually this occurs again.

I never experienced this before on any system I manage.  So wondering if anyone else has experienced this or has advice on where to look/how to fix this.  It's been a real head scratcher for me.  And no, there is nothing obviously different about this particular Mac.  I tend to setup my systems pretty uniformly, as I move between different systems a bit.

Thanks in advance for any/all help with this.