Square One Nana Glue and Nanaz 1st gro

Everything was going great. Entering week four of flowering and starting to frost up. A couple of days ago I noticed a white spot that seem to be powdery on the leaves of one plant. I just figured out it's a hermaphrodite with flowers on top and has released pollen into the tent. The other plants had a nice bushy white hairs on top. Three of them have hairs turned brown now and the fourth one still bushy. not sure what has happened because I have been very careful with temperature humidity watering fertilizer and training. Grrrr. I just posted a question about whether any of the other plants could be saved. Wondering if it makes sense to even let these flower for another three or four weeks or just start over. I am learning. 😟