Well, I scrapped the Advanced Sessions Plugin, and went with SteamCore plugin instead for extra functionality.
The plugin allows me to request everything from the steam server browser, and populate server lists in-game with it, filtering by my AppID. Basically just duplicating the all same info you get from the server browser but showing it in-game. So I’m able to see my dedicated servers now. Then instead of using Join Session node, I connect directly to them with the console command “open steam.xxx”. As shown here: SteamCore & Finding and Creating Multiplayer Games - eelDev
I can still use Find Session to discover player hosted listen servers. But at least now I can populate a list of dedicated servers.
Slowly figuring this stuff out…