Q.Peach Tree No Longer Developing And Inside Has Changed
Our peach tree is flourishing and used to produce peaches but then the following year they didn’t develop past a small size. We thinned it out a ton this year as instructed and now the inside has a white soft seed and it stopped growing again. We can’t figure out what’s going on with our tree and why it stops growing. I’ve attached a pictures of the white pit on the inside. If anyone could help we’d appreciate it.

Certified GKH Gardening Expert
I'm wondering if the leaves of the tree are, also, curling. Premature fruit drop can happen because of Peach Leaf Curl Disease. This fungus can be quite devastating. It can be introduced during pruning if the pruners had not been sterilized prior to pruning.
Other things could include improper soil nutrition, such as high nitrogen and low phosphorus and potassium, or a change in watering habit.
These articles will help:
https://www.gardeningknowhow.com/edible/fruits/peach/peach-leaf-curl.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/test-soil-for-pests-and-diseases.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/making-sure-soil-drains-well.htm
https://www.gardeningknowhow.com/edible/fruits/peach/peach-tree-care.htm