What kind of mold are you thinking it is? It doesn’t look like leaf septoria because the spots are missing the tell-tale yellow halo around the dots. But if it is fungal (perhaps rust fungus), H2o2 won’t work… you’d need a systemic fungicide… one that contains the active ingredient Bacillus or myclobutanil.
This is what Septoria looks like:
Since your environment is hot and humid, you can also create a natural defense by adding Lactic Acid Bacteria to the soil (watering it in). You can find my instructions here. It would be without the molasses… just the LAB.
Even if it turns out to be a deficiency and not fungus, the LAB will be a great addition to your soil.