Dear forum,

I brought home this giant alocasia (I think) from the local plant store, and in 2 weeks time, it has started developing strange symptoms. See photo. On the largest 2-foot long leaf, there is a thinning in the spaces between the major veins at the distal end of the leaf in the areas that are grey in the photo. It is paper thin in those spots! This has developed over about a week. The stalk is also slightly drooping. I'm confused because I know it was not overwatered, and not re-potted. I placed it in a rather dark corner (not by the window as shown) and really haven't done much to possibly hurt the plant at all. Windows are South-facing. Our climate has been dry, but the soil always somewhat moist.

My two more outlandish ideas are:
1. There are tiny white mushrooms growing in the soil. Could those somehow be hazardous?
2. The internet modem and router were within a foot from the pot, and recently there was news of those Swedish 9th graders doing an experiment where no plants grew near the router. Sounds silly, but just maybe?

If you can diagnose the problem, I would love the help.