Welcome to the club, I suppose.
I am eternal optimist, but pragmatic as well. I have tried many avenues and have varying amounts of hits and misses over the decades.
I realize it is geography, luck, happenstance (and other factors) for most part in finding a co-founder.
I also realize a shared experience or pain is pivotal in finding and keeping a co-founder.
MeetUps and CoFounder Dating and other sites are good, but hard to find the ying for your yang (for lack of a better term) by just talking to some random person at a random meetup. It is not impossible, of course.
So no answers here and I haven’t found any myself - yet!