Hello,
For this scenario, if your routers have public IP addresses assigned by your ISP, the simplest way to access the BMS controller from the WAN would be to configure port forwarding rules for the required port(s). A detailed guide on configuring port forwarding can be found here:
Alternatively, and this is the recommended and more secure approach, you can use RMS VPN or RMS Connect to access the controllers without exposing them to the internet. RMS VPN creates a secure tunnel to your devices, allowing remote access from anywhere. Full setup instructions for RMS VPN are available here:
If you still struggle with the setup, could you please share a screenshot of your current remote access configuration for the controller?
Best regards,