Command Blocks created as Impulse have Chain or Repeating Type

When I place a command block, it is set as Impulse, but in "previous output" it show either chain or repeating type and acts as that type. Meaning that even though it says it's impulse it acts as a chain or repeating type. Also the needs redstone sometimes does not work. Switching the type to a new type changes nothing but the color of the block.