Steam and server sessions

Hello, I have been trying for a while to connect my game with Steam. I am using 4.11.1 and Steamworks 1.36. I packaged my game, as soon as I open it, the steam overlay pops op, and I can create a session. However, I gave the game to a friend of mine, and he couldn’t find my server. I use “Find Sessions” blueprint node to find the server. I am using the test app id 480. Here is some settings I’ve done:

in DefaultEngine.ini:

[/Script/Engine.GameEngine]
+NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="/Script/OnlineSubsystemSteam.SteamNetDriver",DriverClassNameFallback="/Script/OnlineSubsystemUtils.IpNetDriver")

[OnlineSubsystem]
DefaultPlatformService=Steam
PollingIntervalInMs=20

[OnlineSubsystemSteam]
bEnableSteam=true
bEnabled=true
SteamDevAppId=480
GameServerQueryPort=27015
bRelaunchInSteam=false
GameVersion=1.0.0.0
bVACEnabled=1
bAllowP2PPacketRelay=true
P2PConnectionTimeout=90

[/Script/OnlineSubsystemSteam.SteamNetDriver]
NetConnectionClassName="OnlineSubsystemSteam.SteamNetConnection"

in my build.cs

PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "OnlineSubsystem", "CoreUObject", "OnlineSubsystemUtils", "Networking", "Sockets", "OnlineSubsystemSteam", "OnlineSubsystemNull" });

PrivateDependencyModuleNames.AddRange(new string[] { "OnlineSubsystem", "Sockets", "Networking", "OnlineSubsystemSteam", "OnlineSubsystemNull" });

in Target.cs:

Type = TargetType.Game;
UEBuildConfiguration.bCompileSteamOSS = true;
bUsesSteam = true;

to load the latest Steamworks version, I changed in Steamworks.build.cs:

string SteamVersion = "v132";

to

string SteamVersion = "v136";

in SteamController.cpp:

#define STEAM_SDK_VER TEXT("Steamv132")

to

#define STEAM_SDK_VER TEXT("Steamv136")

and in OnlineSubsystemSteamPrivatePCH.h:

#define STEAM_SDK_VER_PATH TEXT("Steamv132")

to

#define STEAM_SDK_VER_PATH TEXT("Steamv136")

Do I need anything else to make Find Session to be able to find servers?