I have the same conditions for all my fish (except parvulus, which I keep in a bit lower ph)
but otherwise no big difference concerning humic substances, softness etc.
I had the same problem once with harveyi, and at that time started a thread on the subject.
You can read that here https://parosphromenus-project.org/en/forum/4-Breeding/1364-p-harveyi-males-only.html
With these p.tweediei, there are females, but majority males. This was an unsual big hatch for me, around 40 fry. The harveyi batches was also big.
Most of the times when I breed extensive there seems to be a more normal and even distribution of male females.