Do they really look like bites? Like curved edges perfectly cut? Not the whole leaf but just a scoured out section? That could be a leaf cutter bee, who is lining her nest with soft new leaves. But 3/4 of the leaves are left behind and it doesn't seem to hurt the whole tree.
Or are they chewed with teeth marks, like something is grazing it? Deer aren't supposed to eat Red Bud, but you can't trust deer. But if deer aren't an issue where you are, could it be a rabbit?
Are the edges torn that look like celery strings? That's a sign of grazing, ripping it off.
Or do you mean like a little bug is eating the leaf until parts of it are see-through? Is there any sign of the little bugs underneath the leaf? What's the pattern/shape of the eaten part?
You can spray it with a garlic/chili pepper tea. Put those in a blender with water, strain it into a sprayer. Add a little horticultural oil in the sprayer to make it stick. That repels larger animals and some bugs.
If it rains you'll need to repeat this maybe once a week.
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Life goes on within you and without you - George Harrison