killedByTeam.COLOR doesn't increment upon death

When a player from one team kills a player from another the score for the objective doesn't increment as it should. I have checked several times for typos but didn't find any. I have removed and remade the objective and teams too but it didn't help. I know that the commands are correct because I am able to manually add a point to the objectives and the command block system activates correctly then.

Here is the commands, maybe I am missing something.

/scoreboard objectives add KILLEDBYGREEN killedByTeam.green Killed_by_Green

/scoreboard objectives add KILLEDBYBLUE killedByTeam.blue Killed_by_Blue

/scoreboard teams add green

/scoreboard teams add blue

/scoreboard teams join green @p

/scoreboard teams join blue @p