After building a small structure using Incense Cedar Wood, Planks and Leaves, the next time I loaded my world I noticed that the leaf blocks not attached to any wood blocks all disappeared. I replaced them but the next time I loaded my world the same thing happened. Being aware of this I saw the leaf blocks as they were disappearing...it was raining as well. Maybe there is a logic hole for this mod's leaves such that a block tick update or whatever causes a placed leaf to be checked against whether it is connected to wood or not. Of course, this check should only be performed for leaves that result from the generation of a tree.

Plants 1.12.2-2.10.7