Helix-ui returns 2xx for instance that does not exist

[GrantPSpencer]

Describe the bug

Helix-ui will return 2xx code when you access an instance that does not exist - even if the cluster exists or not. The resources tab does not appear to be throw a 404 and just returns an empty list.

Request Method:
GET
Status Code:
204 No Content

Going to configuration still throws a 404, this is what should be thrown when you try to access an instance that does not exist.

To Reproduce

Go to helix-ui
Modify url manually to enter a fake instance name
Observe 2xx area code

Expected behavior

Throw 404