I say reach out one more time with something specific like, "Little Bobby and I are headed to Rio to feed the ducks at 11 if you want to meet us there!" If no response after that, let it go.
Not all people are instigators when it comes to friendship, and some are very shy. I met some of my best mom friends because I am shy and they kept pursuing me
Otherwise, I say just keep putting yourself out there. Unfortunately, I did not meet any friends through MOMS group or Fit4Mom (although they were pushed on me alllll the time). And, sorry, but Fit4Mom was actually the worst. I am in terrible shape and my baby cried the entire time- it was a disaster the few times I tried it. People on Facebook groups push the Fit4Mom all the time as well- maybe since it is a business? It wasn't for me, but maybe if you are a hardcore workout person?
I've met a lot of friends in random meetup groups, through Nextdoor by scheduling playdates, and just by going to to the same places over and over and running into the same people (like MyGym, Kids Play Gallery, etc.).
You could always start your own meetup group as well- such as "Babies born in 2019".
Good luck!