Q.HOSTA – DAMAGE OF A DIFFERENT KIND
Two mornings ago I noticed one of my Hostas had had many of its leaves pulled or cut out. This morning I found two more with similar damage. They are all the same variety. Other Hostas have not been touched. Would it be a rat, a squirrel, a badger, a fox, a bird or a cat? I should mention that I have been using the new type of slug pellets which , in addition to them not being harmful to birds, the birds actually like them and eat them. Could it be that something is destroying the plants to get at the pellets?

Certified GKH Gardening Expert
That could be a good explanation! Unfortunately, I can't be sure of what is causing it, either. You may catch it in the act at some point, but you could try bird netting.
https://www.gardeningknowhow.com/garden-how-to/bird-netting-for-pests.htm
https://www.gardeningknowhow.com/ornamental/foliage/hosta/page/2