Can't find any session while Steam is running

Somebody help me, please!
At this moment i stuck with this problem for 7 days, and, sadly, Google can’t help me with anything.

I have a project in Steam with my ID, it has 4 types of multiplayer (Epic Session functionality, Advanced Sessions Plugin functionality and connect via IP (also clients and servers from console, but it isn’t in priority at this time).

Problem: if i logged into Steam, ABSOLUTELY NOTHING works, can’t find any session and even can’t connect via IP (Steam Overlay and Steam himself works properly), was tested as 2 clients on 1 pc and 2 different PCs.
If it runs without Steam - all working fine, but, of course, i can’t go with this.

I tried everything in DefaultGame (SteamAuth strings, DefaultPlatformService, etc), opening the ports, changing the ports (from 7777 to 250) - nothing works too.
Someone was talking about maximum/minimum number of sessions shown - it didn’t work too.

If you need screenshots - i can give it (at this moment i don’t know what to show).

(P.S if i didn’t buy page in Steam - probably i would have thrown out this project and go next)

Also sorry for bad English (if it’s really bad).

14 days, no reply, I’m feeling your pain:

7 days, is just a beginning start trying to get this to work. I’ve been 3 months and finally have mine working, no help from anywhere.

My suggestion would be, if you haven’t already or aren’t doing it anyway, is to abandon any hope of using the Steam Servers browser in the Steam application. First of all, you will get NO help from Steam or anywhere else with these issues and I was NEVER able to get any of that to work.

Using Advanced Sessions plugin will work certainly for P2P, but I’ve had massive trouble getting it working for Dedicated server, so I had to cobble up my own, basically spending weeks trying to figure out using the most useless descriptive documentation available.

I'd recommend you build your own server browser, and additionally, you will have to be sure you run each client on a different network. Forget trying any nonsense like hair-pinning and running from the same network. Basically I'm paying for 2 separate internet services and am also renting a virtual server, in order to be able to develop and test.

I have impotently raged and killed numerous keyboards getting it to work. Your frustration is real and deserved. If I wasn’t already about 1.75 years into my project and didn’t already have it working, I can’t say where I’d be, but Unity would probably come to mind.

Keep at it, and you will get it figured out. But you probably won’t get much help here, and you definitely will NOT get it from Steam as they WILL NOT SUPPORT you if you are using a 3rd party engine like UE or Unity.

I know this because I asked and was rejected for it.

Good luck and post here with results or questions, and I’ll try to see if I can help in any way.

It is very disappointing that something as critical as MP has so little useful documentation and support, except for the most rudimentary of tutorial level use-cases.