Apple Tree Vanishing Stem Tips and Leaves

If I could get pics, I’d post 'em. I was looking at some young apple trees and noticed that the tender new growth was brown at the end. There was no growth tip - just what appeared to be a roughly broken off end of new growth on the scaffold. On one, I saw that there was a second break less than an inch farther along. Then I noticed that on these same trees and branches leaves were missing, but the leaf stems were still in place. No fallen leaves or young growth was to be found on the ground.

All of the affected trees were planted either this March or two years ago. All noted damage was within 4 feet of the ground.

Even though there are a multitude of munching and sucking insects here, I don’t know of any that make such clean breaks. Animal? Illness? I suspect squirrels have been stealing ripening stone fruit, but the limited height, and the fact that I doubt these thin branches could support their weight if they climbed trees, doesn’t put them at the top of my suspect list. Also, I know we have rabbits, but they are small and unable to reach that high.

What do you think might be doing this?

I see something akin to that when I withhold water to slow growth and increase fruit brix. It’s one indicator I use to time irrigations.