Can't Change Incorrect APN Settings

I have a brand new, unlocked Nokia XR20.

Mobile data works fine, SMS messages send and receive without issue. I cannot receive MMS messages (group texts, or pictures), however I seem to be able to send them. My MMS proxy and port are incorrect, however the APN settings are all greyed out and cannot be edited. There is also no "+" for me to add a new customized APN.

I have tried restarting, resetting to default, and a suite of recommend steps from the manufacturer all the way to a full factory reset. I have even spoken at length with Telus tech support about this issue, which is apparently known but only in older devices.

Has anyone else experienced this?