I finally figured out why my Ficus lyrata keeps dropping leaves—it's the drafts from my bedroom window, not underwatering like I thought

I finally figured out why my Ficus lyrata keeps dropping leaves—it's the drafts from my bedroom window, not underwatering like I thought! I moved it a meter away and it's already looking happier after three weeks. Has anyone else had this problem? I'm still confused about the right watering schedule though. Should I let the top inch dry out completely before watering, or does the humidity in my tropical climate change that rule?