repeat testfor block does not update when unpowered

I have a testfor command in a block set to repeat and redstone needed, When I cut the redstone, the block will continue to emit a signal, and I have to set it to impulse for it to stop. putting it back in repeat does not start the signal until re-powered.
I feel like I should precise that what the block tests is still true when I de-power it.

edit : works the same if I am in survival mode.

command inside is : /testfor @a[name=MA_GE,m=1] (same for : /testfor @a[name=MA_GE,m=0])