Copper Bulbs Not Getting Hard Powered

Normally when blocks get powered directly they power the surrounding blocks too. I call this situation "Hard Powering".

But copper bulbs don't get hard powered. No matter which power sourde i use they don't power up surrounding blocks.

Tested Versions: 1.21, 1.21.1, 24w39a (with redstone experiments enabled), 24w39a (without redstone experiments enabled)

Gamemode: Creative, Survival and Adventure