21w06a Giant Spruce Trees vanish when grown in large caves

Go to an area where there is plenty of room to grow the tree, place 4 dirt on the ground in a 2x2 making sure nothing is within 2 spaces from the dirt...Plant 4 saplings, one on each dirt. Giant spruce will grow, but when you leave the spawn radius and return only 4 podzol are the only thing that remains.