SIMCOM A7670C cannot connect to HiveMQ Clound

I’m facing an issue connecting SIMCOM A7670C to HiveMQ. Please help me fix the error (+CMQTTCONNECT: 0,31)
a7670cerror

Hi @caotheanh,

Welcome to the HiveMQ Community! It’s truly exciting to see your interest in MQTT and the HiveMQ broker. Your enthusiasm is greatly appreciated.

Thank you for sharing a portion of your program.

To connect to the HiveMQ Cloud Serverless broker, it’s crucial that your client supports TLS-SNI and presents the correct root CA. You can delve into the specifics in our comprehensive knowledge base articles:

However, from the segment of your program you provided, it seems there’s a gap in demonstrating how you’re enabling your device for TLS-SNI or uploading the server certificate. Consequently, it’s possible that your device isn’t properly configured for TLS-SNI or isn’t utilizing the correct server certificate.

Please take a moment to review the documentation provided by HiveMQ regarding TLS-SNI support and server certificate configuration. Ensuring that your device is configured correctly to support TLS-SNI and presenting the correct root CA is paramount when connecting to the HiveMQ Cloud Serverless broker.

I hope this guidance proves helpful.

Best Regards,
Dash from HiveMQ Team