This happens when you're not using our towers to access the cellular network. When you're roaming, your device is trying to connect to another carrier's tower because our signal has dropped.
We'd probably need to assess the coverage status in your area and check if there are any recent reports of service outages impacting your area.
You can send us a private message with your current address and let us check your service status. I'll be glad to help you with that!
Social Care Agent