Unreal Networking - Find Session - Router Settings

Hi everyone,

my question is about the “Find Session” functionality in Unreal.
Im trying to use this in a LAN networking.
My question: What do I need for router settings to support best “finding” while using “Find Session”?
I’m asking this because with some routers I don’t have any problems, with some other routers I have to search more often to find a session.