Background: I have a Wavecom GSM modem. If I put a 2Degrees SIM it sends SMS fine, similarly if I do the same with a Vodafone SIM.
With some help from johnr, I ported my 022 number onto my Vodafone SIM, however my modem will not send/receive SMS now and I have no idea why. What makes it more confusing is if I take that SIM out and put it in a budget Nokia, it sends/receives fine.
What's changed that my modem won't send/receive now?