Hi @zenric, as you have no reply, I propose that you may have misunderstood the conitional mood in the modal verb “will” as used by a French speaker.
I think that @smu44 is proposing you study yourself in detail the APNs in use in a) the “working” and b) “non-working” condition .
APN numbers are sometimes found to change by the carrier. The /e/ device has many APN’s preconfigured, but the carrier changes one small element and a certain service is dropped. In the first instance this is down to the carrier. (Speculating personally, maybe the carrier makes use of Google to keep Andoid devices up to date with these changes?)
I add this link [LIST] APN Values for Service Providers to demonstrate APN in detail – but historical information is not as good as real time information you could collect by comparing a “working device” with a “non-working device”.
https://community.e.foundation/search?expanded=true&q=APN%20order%3Alatest