When i choose ranked or quick match there is only searching nothing more happens. Someone can help me?

I think the problem is that very few people play the GOG version. Note that at the moment, GOG and Steam use separate servers, as well as separate servers for Windows, Linux and Mac, resulting in many segregated servers.

So are there any plans to address this issue? It's kind of a biggie, y'know.

Last I heard Team17 was working towards getting cross-platform multiplayer in Steam. I don't know where they are right now, but they will probably like to get Steam unified first, before connecting it with GOG.

Do somebody know something new about this topic? I would love it to play it online :(

Fairly sure someone from Team17 said that it was due last month or some time around April.
Check steam forums, it was mentioned on there.

P.S. Any games with multi player, you're always better off playing via steam if there's no cross play from game release.
There's a tiny amount here play online whereas steam, there's a hell of a lot more.

After the workshop update is confirmed to not make it here (and items produced ONLY go to workshop) I wouldn't count on it. If crossplay does become a reality it'll only half work, unless there's another way to get workshop content.