My coin plants have been battling fungus gnats the last few weeks, and I actually ended up having to replace the soil, mixing in diatomaceous earth, and topping with gnat repellent gravel. I think we are finally finished with the gnats, but in the meantime, I noticed the leaves curling and most recently these spots forming. I check the top 1-2 inches of soil to make sure it’s dry before watering which is usually about every week to week and a half. It’s facing a NW (more west) window. She’s been great ever since I’ve gotten her, but the last few weeks have been a struggle. I didn’t know if the stress is causing this, or if I am doing something else wrong. Any suggestions are much appreciated! Thank you a bunch!