Using a scoreboard objective with the criteria killedByTeam.red and all other team colours doesn't work. It registers the objective and manually changing the value works, but it does not track it automatically. Ran the same world in a vanilla server and it worked properly.

Steps to reproduce
/scoreboard teams add red
/scoreboard teams option red color red
/scoreboard teams join red @p
/scoreboard objectives add iWasKilledByTeamRed killedByTeam.red
/scoreboard objectives setdisplay sidebar iWasKilledByTeamRed
Proceed to kill any other player on the server.