Data works, but only sometimes

Check first

Open your SIM settings and confirm the KnowRoaming line is still the one selected for data. If it isn't, that's the whole problem: set it back, and on iPhone turn off Allow Cellular Data Switching. See Phone reverting to the home SIM automatically.

Causes, in order

Your phone keeps moving data back to your home SIM

Restarts, updates, and iPhone's Allow Cellular Data Switching all do it. Data works while the KnowRoaming line is selected and stops when the phone flips back. Turn the setting off and re-select the line; see Use your KnowRoaming plan for data instead of your home SIM.

You're moving between networks

On foot, on a train, or in a car, the phone hands off between towers constantly, and each handoff is a brief gap. On a regional plan, a border crossing is a longer one while the phone registers on the next country's network. Give it a minute after you cross.

You're at the edge of coverage

Some spots sit right at the limit, connecting and dropping rather than failing cleanly. A street over, a window, or a step outside usually settles it.

Low Data Mode or Data Saver is on

Both hold back apps on mobile data, so some things load and others quietly don't. Turn them off for the KnowRoaming line while you travel.

Several apps refreshing at once

On a modest signal, a phone catching up on background refresh can feel patchy for a minute. If it's constant rather than occasional, see Speeds are slower than expected. If it stopped and stayed stopped, see Data stopped mid-trip with no warning.

Still not working?

Still not working? Message us on WhatsApp at +1-888-357-7347 and include four things: your ICCID, your order number, your phone model and OS version, and what you've already tried.