Tridents don’t deal damage in spectator mode

Built a Creeper farm with trident killer and wanted to watch to see how fast creepers would spawn. I then used the command /gamemode spectator then flew into the wall to watch the creepers land in trident killer and realized they stopped dying. As soon as I used the same command to go back to creative they started to be killed again. (Use pigman spawner in video because spawn rate is faster)