When rubber wood fence posts have aspectrus seeds planted on them, any contact with water deletes the fence post but not the seed. Fence post does not drop to be collected. This could be due to the fence post taking on the same entity tag as the aspectrus seeds. Water deletes any plants it touches, so maybe planting the seeds on the fence combines them into a single "plant" block that can be deleted by water like all other plants.

Version: 1.12.2 (14.23.5.2854)

BL version: 3.7.2 (latest)