I would let it go dry until it starts to droop. This will tell you if you been over watering. Perhaps your hole holds water well and can go 4 to 5 days before it needs water. Let the plant tell you when it needs water. A few times letting it droop slightly will tell you how long it can go without water. Then water to what you find out. While doing this see if the leafs lose the claw.
If you think it is the heat try a sun sail/shade for a few days and see what happens.
Is your hole clay? Perhaps it wetter down there than you think. Try one of the cheap moisture meaters. See what it reads.
