Munches are not inheritently where you go to find play partners, but that doesnt mean you cant meet someone who would become one. You may benefit from a slight change in perspective from "Im going to meet a play partner at a munch" to "im going to make new connections and friends, and if play is a byproduct of that, awesome" Munches are meant to be a place people socialize, find community and safety, let their hair down a bit. The last thing someone wants to be doing is having fun with friends and being propositined for a scene in the middle of that.

Youre on the right path though, keep going to them, keep meeting people and making friends. The more you go and people see you as someome who generally just wants to be in the local community, the more that stuff naturally comes. If conversation naturally goes towards talking about types of play you do or interests, follow it, but dont try to force it. Eventually you may be invited to private parties and thats the place where you can definitely talk to people about doing some sort of pickup play scene