Edges turning black?

Hi everyone. My FLF has lost a few leaves these past two weeks. And the leaves at the bottom have developed the black edges. The newer top leaves look fine though. I’ve had it for about two months. Lighting is by the window behind a curtain, it gets a lot of filtered light. Humidity hit or miss, I live in Hawaii.

There is a chance it’s overwatered. It’s not usually, but last watering I was overzealous.

Thanks everyone!