Old thread but some useful info, to direct connect to a steam dedicated server, you need to use open steam.generatedServerNumber rather than the ip of the server as steam seems to obfuscate the server ip and instead gives it that id.
you can find the id of the server either querying the steam oss for the connection url or looking on the steam clients servers browser, it will look like a int64 seam id but usually starts with 90***