Ooharabeni Asian Pear

I bought this one several years ago and the deer and the pear slugs love it. The deer would stick their heads through the fence to eat the leaves and then get their heads stuck and run off with the fence leaving it crumpled out in the woods. I had to wrap the wire fence with deer net and then stake the whole thing down with 2 fence posts. A little copper spray stops the pear slugs but has to be redone a few times each year. This year we finally got 6 beautiful pears that tasted like the best of both. We are looking forward to this tree getting bigger and more productive.

I planted this tree 5 years ago in my food forest along with several other fruit trees and it hasn't grown any height or limbs in that time. All the others (another asian pear and several apple trees) seem well established and have doubled-quadrupled their starting height and are producing fruit. It puts out lots healthy leaf bunches from the trunk each year and last year I did get 2 small (delicious) pears from it, but it remains at the 3 feet it came as. Same planting, spring fertilizing, deer fenced, and summer watering routine as my other trees every year. It gets full sun morning to mid afternoon, then partial-full shade the rest of the day. So I'm stumped as to why it's so, well, "stumpy." Including pics of tag, height with watering wand for scale, and original top cut. I'd love a response with any suggestions to help get this little tree growing.