Can also confirm for 1.13.1.
It seems to only be an issue when the item on the slab is next to a solid block; in open water, items seem to float up normally when on a bottom-slab.
Unable to reproduce in 1.13.2 or 18w43b. Items now will float up from properly-waterlogged slabs unlike they did in the 1.13 snapshots.
2018-02-18, 04:45:00 PM UTC
MC-142936
Matthew
Can also confirm for 1.13.1.
It seems to only be an issue when the item on the slab is next to a solid block; in open water, items seem to float up normally when on a bottom-slab.
Unable to reproduce in 1.13.2 or 18w43b. Items now will float up from properly-waterlogged slabs unlike they did in the 1.13 snapshots.