/spawnpoint not working in command blocks

I am trying to make a PVP map with two teams, red and "blu". I have custom spawning systems to count whenever a person dies to add it to a death counter. The thing is though, /spawnpoint doesn't seem to work with the tag @a. I will include a couple screenshots, but when I use /spawnpoint (any co-ords) as a player and do /kill, I immediately spawn where I changed it, but with the command block, it says in the output section that "AGuyWhoIsBored's [that's me] spawnpoint was set to ...", but when I do /kill, it sends me back to where I set my spawn when I changed it as a player. I really hope this gets fixed as I really count on it btw this is on a server