they are getting too dried out. I also have Elephant ears growing in a container, and I have to water daily, drenching it a lot, but such is our weather here, just too dry. But thankfully it will continuously do new leaves, just expect that crunchy edges. Our lousy humidity levels really hits them hard.
In my old homeland, these plants are growing in swampy-like environments and getting daily rains. So it is the total reverse of our weather here in NorCal. It can take the heat but needs to be kept very moist to thrive better.