It looks like there was an issue with the passwords, as I see a boatload of errors like this:
[2020-07-27 23:30:40] NOTICE: res_pjsip/pjsip_distributor.c:676 log_failed_request: Request ‘REGISTER’ from ‘“3001” sip:firstname.lastname@example.org’ failed for ‘10.49.1.64:5060’ (callid: email@example.com) - Failed to authenticate
(I put xxxxx in for the actual extension password)
I reset a phone to defaults, same issue.
When I manually enter the extension password into the phone GUI it rebooted and registered.
Have two offices full of down phones now…