Q.Freshly Planted Birch Tree Never Leafed Except At Base
Not sure why, my freshly planted birch tree started to bud. Then it stopped and after a few weeks the base was shooting out leaves like crazy.

Certified GKH Gardening Expert
It sounds like the top has died off, and it is trying to re-grow from the root! This will indicate that the transplant has failed.
Because this could be one type of Birch grafted to another, it is likely that you have lost the top graft. In this case, the rootstock will take over.
https://www.gardeningknowhow.com/ornamental/trees/tgen/what-is-a-graft-collar.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/how-and-when-to-plant-trees.htm