A strange tree

I planted a very short tree, the leaves are only one grid away from the ground.There is also a beehive on the tree, when I get close to this tree, I can go straight through a whole tree(Tree trunks are not included)and walk freely through the leaves even if I go out, I can come back in at any time, I thought it was strange, so I didn't destroy it     (All of the above are encountered in the survival mode)