On a dual-line phone, only one line carries mobile data, and the default is often still your home line. Open mobile data settings and confirm that the selected line is the travel eSIM. This is by far the most common reason for no connection on arrival.

Also check that the line is enabled, rather than only installed. A profile can be added to the phone and left switched off, and it looks almost the same on screen as an enabled one.

A travel eSIM connects to a local network as a visitor, so many phones require data roaming to be enabled for that specific line. This is different from enabling it on your home line—which is best left with roaming off—and they have separate switches.

Once everything is correct, give it a few minutes. Registering on a new network after landing can take time, especially in a crowded airport where thousands of phones are doing the same thing. Toggling airplane mode once helps; doing it repeatedly just wastes battery.

If the line appears registered on a network but nothing loads, check the APN against your provider’s details: it is the one value you sometimes need to enter manually. If the phone cannot register on any network at all, the usual cause is the device rather than the plan, often because the carrier that sold it locked it.

At that point, contact support with useful information: which line carries data, whether roaming is on, which network appears, and exactly what the screen says. A message with those four details can be resolved in one reply; one that says “it doesn’t work” takes three.