I bought a Fiddle Leaf Fig tree from a local nursery a month or so ago. It was looking okay, just a couple brown spots but now it seems the brown spots have grown some. I've also noticed little gnats in the soil, so I thought maybe overwatering (although I've only been watering it about once every 2 1/2-3 weeks and I make sure to water thoroughly but then dump the tray underneath) but then yesterday I noticed this light-greenish/white mold looking stuff (pictures attached) on top of the soil. Is it fungal? Or actual mold? Would an insecticidal soap help? Could it not be getting enough sun? I have it in indirect light between a sunny window and my front door with a window. I really love this plant and would like to keep it going, but I'm clueless.. Any suggestions would be appreciated.