Weeping fig losing leaves

diggingdoris

My indoor fig is suddenly losing masses of leaves. It's been in the same position by a glass front door for 20 years and is 5ft tall.  I've been watering it a bit more than usual as we've had such scorching weather and it gets midday sun there. I've looked on websites and some say let it dry completely before watering, others say never let the compost dry right out. So I don't know if my watering has caused this or not. I know they usually lose a few leaves now and again, but I've never had this before.