Going by the pics, it appears you have less than 8 weeks left. But regardless -
Keep on that dr Zymes treatment as it recommends for fungicide use. Dr zymes worked decent for WPM for me but not pests. Anyhow, keep consistent with what it says (using every couple days I believe)
It should eliminate and keep mildew at bay. There’s always mildew spores in the air, you just want to stop it from having a suitable environment to thrive in..