[Bug] Cannot find or connect to dedicated server

Not sure if this is a bug or whatever but since the Patching Optimizations patch I have been having issues searching and connecting to my dedicated server. Now I'm not sure if it is the game or my host (Streamline-Servers) but I can no longer see my dedicated server in my favourites or history, can't search for it, and cannot directly connect to it. I can add the server to Steam's Favourite servers and it is showing up there but that's it as I can't even connect to the server via Steam just like the direct connection ingame via the dedicated server browser nothing happens. No error messages or anything.

It's starting to annoy me as I can easily find thousands of other dedicated servers but just not mine. So posting here to try and figure out whether it is server-side, game client side or both. Knowing my luck none of the above...