Debugging is not always a matter of attaching the debugger to the server code or the client code and stepping through. Sometimes, the secret is hidden in the data going back and forth and it's not that obvious to understand this with the debugger. With logging enabled, Fiddler, the browser, and the performance counters, you should now be able to both debug and find potential bottlenecks in your system. Although, it might feel a bit primitive compared to the tools that you might be used to when developing vanilla web apps, they are very detailed and should be of great assistance.
In the next chapter, we will look at how to self-host SignalR in your own application.