Rain can't go through sculk veins when placed on a wall, which can lead to create some kind of roof with them. This is inconsistent with other similar blocks, like vines and lichen.
Linked issues
is caused by 1
relates to 5
MC-273230
Several blocks are incorrectly ignored by/present in certain heightmaps
Open
MC-259109
Rain/snow goes through chorus flowers and chorus plants
Open
MC-261164
Sniffer eggs don't block rain
Resolved
MC-248299
Rain and snow can go through coral but can't go through dead coral
Open
MC-260599
Rain cannot pass through banners
Open
Can confirm in 23w03a