Using Atlassian MCP within Cursor error 400

[Daniel McKenzie]

Hi,

I am trying to connect curson on https://mcp.atlassian.com/v1/sse, it brings me to the login page, I accept, it moves me back to cursor to accept the redirect but when I do I get this error :

2025-06-23 10:21:59.398 [info] [user-Test] Received OAuth callback with code

2025-06-23 10:21:59.755 [error] [user-Test] Failed to complete OAuth exchange Token exchange failed: HTTP 400

My mcp config is :

"AtlassianMCP": {

      "url": "https://mcp.atlassian.com/v1/sse"

    }

Any idea what can cause this, some collegues are able to log on the corporate Jira with the same setup? What am I missing?