Leaves sometimes replace water when the tree grows up instead of getting waterlogged

Leaves replace water when the tree grows up instead of getting waterlogged.
Expected behaviour:
When the tree grows up with water above, the water doesn't get replaced but instead leaves get waterlogged.
Actual behaviour:
Leaves replace water despite being waterloggable.
NOTE: This does not apply to mangrove propagule or azaleas, only to regular saplings.