apparently some carriers support sms over ip. if you have wifi it could be it.

Yes, I answered your earlier question with some ideas, but you confirm here that you are enabling Wi-Fi, and messages can go over Wi-Fi under the right circumstances. There's more than one way that could happen.

Like WiFi calling, you can also send and receive texts over WiFi if your network provider supports it. This is expected behaviour. Airplane Mode disables the cellular radio and works as it should, mobile network features outside of the cell network is a separate thing.

You can prevent this by disabling the SIM, if you want to. But as nostr:nprofile1qqstnr0dfn4w5grepk7t8sc5qp5jqzwnf3lejf7zs6p44xdhfqd9cgsppemhxue69uhkummn9ekx7mp0qywhwumn8ghj7mn0wd68ytnzd96xxmmfdejhytnnda3kjctv9ulj6hdh says, it does not mean the cellular modem is communicating with the network.

Sounds like the phone doesn't really disconnect from the network when you tell it to. You can't trust them. I keep location off on my phone. I've always wondered if it really turns off location or just makes it check location less frequently. I sure miss the days when I could easily pull the b...