Keep two records
Write down the model and software version, then identify how the service expects the MAG to connect. A portal-specific failure can occur after the device has already connected to the network. If the device cannot connect at all, test the network path before editing portal settings.
Test with a stable connection
If your model and setup support Ethernet, compare it with the existing connection without changing the portal address or account. Once network access is confirmed, check the written portal and account details privately. Give support the exact error stage, not the private address.