Why do I have to enter the APN data on my “Akita” manually?

Moschatus

When I was in Austria, roaming didn't work. After much searching, I discovered that the Pixel 8a with GrapheneOS was missing the APN values for the roaming partners. In Germany, I had already had to enter the APN data for Sim24 myself.
Is it normal to have to search for APN data online and then enter it manually?
Would it also be missing on the stock ROM?
Doesn't the APN data normally come with the firmware?
Would it make a difference if the device were logged into the mobile network with the stock ROM before installing GOS?
I use the RethinkDNS app. Could something be blocked that is needed to obtain the APN data?

de0u

Moschatus Is it normal to have to search for APN data online and then enter it manually?

Semi-normal -- carriers and others post APN data, and the OS has an APN editor, because sometimes it's necessary.

Moschatus Would it also be missing on the stock ROM?

Maybe. It's hard to say without trying.

Moschatus Would it make a difference if the device were logged into the mobile network with the stock ROM before installing GOS?

No. APN information does not survive across an OS installation (almost nothing does).

Moschatus Doesn't the APN data normally come with the firmware?

A "carrier configuration" database is part of the OS (not part of the firmware).

Moschatus I use the RethinkDNS app. Could something be blocked that is needed to obtain the APN data?

Unlikely, unless regular GrapheneOS system updates are blocked.

Overall, unless you were to disclose which Australian carrier(s) you had trouble with and somebody were to dig around in carrier configuration databases, it's hard to know what went wrong.

Moschatus

de0u Overall, unless you were to disclose which Australian carrier(s) you had trouble with and somebody were to dig around in carrier configuration databases, it's hard to know what went wrong.

These Austrian (not Australian) carriers were A1 Telekom Austria and Hutchison Drei Austria.

de0u

Moschatus These Austrian (not Australian) carriers [...]

Oops, my mistake!

Moschatus [...] A1 Telekom Austria and Hutchison Drei Austria

I don't live in Europe, but offhand I've never heard of Sim24, A1 Telekom, or Hutchison Drei. That leads me to suspect that they might be toward the smaller end of carriers, perhaps MVNOs, in which case carrier-config information for them might not be ubiquitous.

Anyway, now that the carrier names are on the table perhaps somebody who enjoys digging through carrier-config databases might weigh in. Perhaps especially if you are in a position to indicate which fields and values you needed to fix.

Moschatus

de0u Perhaps especially if you are in a position to indicate which fields and values you needed to fix.

None of the fields were pre-filled. So I had to enter all the information required for the provider myself.

Moschatus

de0u I don't live in Europe, but offhand I've never heard of Sim24, A1 Telekom, or Hutchison Drei. That leads me to suspect that they might be toward the smaller end of carriers, perhaps MVNOs, in which case carrier-config information for them might not be ubiquitous.

Another person was with me in Austria and too used a SIM card from Sim24 in an older iPhone. Roaming worked fine on the old iPhone, but not on my relatively new Pixel. For this reason, I can't help feeling that GrapheneOS must be to blame for the problem.

de0u

Moschatus Another person was with me in Austria and too used a SIM card from Sim24 in an older iPhone. Roaming worked fine on the old iPhone, but not on my relatively new Pixel. For this reason, I can't help feeling that GrapheneOS must be to blame for the problem.

You can feel that, and it may even be true. But carrier configuration on iPhones comes from Apple, while carrier configuration on GrapheneOS comes mostly from Google. If a friend traveling with you had been running Google's stock OS on an 8a and had experienced a different outcome than your 8a running GrapheneOS, that would suggest an issue with GrapheneOS.

Moschatus

de0u But carrier configuration on iPhones comes from Apple, while carrier configuration on GrapheneOS comes mostly from Google.

I have to admit, that's a good point. Do you happen to know whether the APN database is also updated along with the GrapheneOS updates?