Possible solutions:
1. Check your node's JCC version to ensure you are using 37764 - 4.43.1.0 MCP Update as in the screenshot. The node in the screenshot is random choice.
2. Replace the host:port portion in the MCP server URL with this node's public IP. You can find it in the following path:
Waffle Menu → Monitor → Infrastructure → (click on the relevant node) → Additional Details → Public IP.
The reason is that the host:port is often not publicly accessible. Therefore, you need to fill in the public IP.
The url will looks like: https://{node's public ip}/mcp/{server id}/mcp
In addition to the two points mentioned above, I noticed you have a load balancer. After solving the current issue, you can try not selecting a specific node when creating the MCP server. In this case, the server URL will automatically use the load balancer's URL, avoiding the need for manual replacement. As long as the network where your MCP client is located can access the load balancer, this approach should work.
