Unable to modify default APN or add "duplicate" APN

someuser64

I'm unable to modify the default APN since everything is greyed out. Is this expected?

I also can't just add a new entry with the similar settings because if you use the same domain name for the APN text box you are unable to save and get the message, "Duplicate apn entry."

I am running the latest Android 15 stable build 2024102100 on a Pixel 8 Pro.