My leaves got dry and waxy at one point. Never did figure it out. But what kind of soil do you have it in? The two yellower leaves look like there not getting enough food and the tops of the plant look like how my plants looked, kinda fried and dipped in a thin coat of wax. Are your leaves curling at all? This is interesting! Sorry I'm not a huge help, but I am super curious. be interesting to know what it is.