When you test a Testforblock command it should find directly we’re a block located at the same data.
Example: /testforblock -80 -58 -14 polished_blackstone_button ["button_pressed_bit"=true,"facing_direction"=5]
Bug: The command repeater shouldn’t trigger the redstone comparator if the button wasn’t press yet on that specific location.
This issue is being tracked at MCPE-194284.