I don't think so that this is a duplicate of MC-134366 because this isn't about conduction through this block, it's about conduction "around" this block. Logically seen the powder bridges over this block - it sticks at the outer edges.
I've found out the exactly same behavior happens with upside down stairs. The redstone signal travels from bottom to top but not in the opposite direction. I assume that these are not the only blocks affected by this behavior.
And something about consistency - why (see picture) works the version at the bottom if sea lanterns didn't conduct redstone signals ?
CommLan
I don't think so that this is a duplicate of MC-134366 because this isn't about conduction through this block, it's about conduction "around" this block. Logically seen the powder bridges over this block - it sticks at the outer edges.
I've found out the exactly same behavior happens with upside down stairs. The redstone signal travels from bottom to top but not in the opposite direction. I assume that these are not the only blocks affected by this behavior.
And something about consistency - why (see picture) works the version at the bottom if sea lanterns didn't conduct redstone signals ?