Glow Lichen yields 2 items when breaking corner-grown faces in Java Edition 1.21.11

When glow lichen grows around a block corner (similar to vines), and multiple faces occupy a single block space, breaking it with shears sometimes yields two glow lichen items instead of one. This behavior differs from normal glow lichen or cave vines, which should only drop one item per logical placement.

Glow lichen cannot be placed twice on the same face by the player, so this situation only arises through natural growth over block edges. The engine treats the corner growth as one block internally, yet the loot outcome suggests two separate drops.

Steps to Reproduce:

1. Find or grow (with bone meal) glow lichen so that it spreads over a corner (two adjacent faces attached to one block).

2. Break the glow lichen with shears.

3. Observe the dropped item count (should be 1 but it actually are 2).

Expected Result:
Should consistently drop only one glow lichen item per block space, as with normal glow lichen growth and like vines do.

Additional Info:
May be related to internal block state handling of multiple attached faces on a single block. Might also be inconsistent with existing vine/lichens drop logic.

Why is it a bug, not a feature? → Vines act differently and just drop one Item in the same case.