Take your time when watering. If you're watering every other day you shouldn't have a problem with drying out. I suspect you let them get too dry and then water too fast. Sometimes I'll have a few pots that want to do that in the last week or two. Give them a little water, wait 5 minutes and repeat. Continue until plants are thoroughly moist. By adding a little at a time the medium will expand and fill those dry gulleys that funnel water out. Water a little slower in the future.