Specifying the correct Method -- "https://" in this case -- is definitely necessary.
The agent code would infer the default TCP port based on the method. But it certainly will not infer the method to be used based on the port. (The method is explicitly given.) The OP seems to know the server is listening on 8080, so it should be "https://yaddayadd:8080". That being said, it's not common for https to be on 8080. So maybe the OP has two problems; using "http://" when it should be "https://" *and* aiming at TCP/8080 when it's actually somewhere else.