Testfor command not working with a fake player

when having "testfor @a[score_test_min=2]" in a command block, adding a fake player like (/scoreboard players add test etc.) and add points in won't output a redstone signal (using comparator) adding a real player thats on the server works, also running Vanilla Server also happens in singleplay

Re-Produce Steps

1. Place a command block and type "testfor @a[score_test_min=2]" Put a redstone Comperator on any side

2. Link a timer to the command block

3. type in chat "/scoreboard objectives add test dummy"

4. type in chat "/scoreboard players add testplayer test 1"

5. repeat "4" again and no redstone signal is outputting

6. try all steps but on step "3" change testplayer to your username

Thats it hope people can Re-Produce