My wife and I found it particularly difficult to get a signal on our recent trip to Australia. Both of us have the same phones - Honor 70 Lite, less than a year old, and both of us have 3 Pay As You Go SIMs which have always worked in the past.
In other countries, and in Australia in the past, we've picked up a roaming network almost immediately we've arrived, but this time all we got was 'No Signal'. I could see three providers - Optus Vodafone and Telstra and tried changing the Network Provider from automatic to manually selecting each in turn but no joy.
We only needed to make one call while we were there, but the ability to receive calls and texts while we were there would be useful - particularly as one of our payment cards used 2FA by sending a text.
It was only while I was experimenting to see if I could fit a local SIM that I found, purely by accident, that by turning off the SIM in the 'SIM Management' setting, leaving it for a while (when it would change from 'No Signal' to 'Emergency Calls Only') then turning it on again, that I could get a connection to Telstra. Sometimes it took a few tries but it generally worked. Once we got a signal it stayed until we turned off the phone.
As our phones work perfectly in other countries I would suggest that this is a particular Australian problem. I tried internet searching for solutions and there were suggestions that it was to do with their recent shutdown of 3G services and the Government blocking certain IMEI numbers - but in that case our phones should not have worked at all. It's certainly not very friendly to International visitors.
Be aware that, if you're going to Australia, your phone might not work and allow for that before you go.
