On the Monitoring page, if nothing happens when you click on a node (server, instance or database) in the tree or a performance counter, check the following solutions.
Solution 1: Have you just installed SQL Governor within the last hour? If yes, simply wait until an hour has passed and check again. It takes some time for SQL Governor to configure the performance counters and alert limits based on the first data points.
Solution 2: Is SQL Server Agent running on the instance where SQL Governor is installed? If not, restart the agent. You can manually run the job called DB Governor log --> input, or you can wait for agent to run it automatically (it runs once per hour).