This damage looks like caterpillar feeding, or possibly a leaf eating beetle. Its impossible to say which species without seeing the organism. We recommend you look for caterpillar frass (little black droppings) underneath the damaged leaves, and also look for the caterpillar(s) itself, or some kind of cacoon on the underside of all the leaves. If you don’t find any of those, it could be a beetle or a weevil. These insects may feed and then move on, or they may lay eggs on the leaves or in the soil around the plant. For caterpillars that are present you can either pick them off (including the cacoons) and dispose of them or use a Bt (Bacilius thuringiensis) product if they are numerous. If you find beetles or their eggs, send us another photo and we’ll look at it again.