The family is all on prepay 2Degrees. We have a mixture of phones, but one has an annoying problem. It is an Oppo A5 2020. All family phones get 'standardised' with Microsoft Launcher, and the default messaging app is replaced with the generic Google Messages app. The issue is sometimes the Oppo fails to receive SMS messages. I haven't managed to manually reproduce the issue, but it has happened numerous times. I suspect it's when the phone hasn't received a message for a while, though as I can't reproduce the issue I can't be 100% sure.
As we are all on 2Degrees I can't be sure if other providers show the issue too. Unless someone said something we wouldn't know.
The SIM did not present this issue in the previous phone. On the sending phone there is no indication that the message has not been delivered. On the Oppo, the message never appears.
Any suggestions as to what might be going on here?