Sorry you haven't found folks in your age group at the meetups you have been to...
I recommend two basic things:
1. Be patient. Keep going to the meetings. If everyone just went to one or two meetings then gives up because there is nobody in the right age-range, then there never will be... I have seen things like this happen in our own poly group, but on a regional basis "I signed up but am not going back cos there aren't enough other people from my area.". Well, if everyone thought that way nothing is going to change.
2. Is there are reason you are restricting this to folks around your own age? I have always tended to find that physical age is deceptive - mental age is important when it comes to good relationships - and I don't just mean maturity, I mean ability to have fun.
So both ways, I would recommend sticking with your local group. At the worst you will make some new friends. And then, maybe, one month, someone will walk through the door that wows you...
"Listen, or your tongue will make you deaf." - Native American Proverb