I suspect snails or slugs but don't see any trails that would evidence this.
What Could Be Eating the Leaves on Our Calla Lilies
Certified GKH Gardening Expert
It could still be slugs or snails. Setting out a pan of beer will determine it or not. It could also be rodents. These articles will help too: https://www.gardeningknowhow.com/plant-problems/pests/organic-snail-control-how-to-control-garden-snails.htm