Copper bulbs are broken, confirmed to be broken by KingBdogs who said 1 tick delay was correct.

Basically, copper bulbs are broken rn because someone misunderstood what they were supposed to do, and filed a bug report for them taking 1 game tick to activate. KingBdogs said on twitter that the 1 game tick delay for copper bulbs to activate was correct, but the false report contained an actual glitch pertaining to the speed of crafters, so one of the devs fixed the crafter and set it to a 4 tick delay, but also set the copper bulb to a 0 tick delay without knowing that it wasn't an issue.