dispenser shoots twice when connected with repeater

Composition:
3 dispensers, 3 repeaters (one tick, two ticks, three ticks), a lever, a button

What I expected:
When I press the button, the dispensers shoots the fireworks with delay. When I release the button, nothing should happen (out).
When I put the lever on on, the dispensers shoots the fireworks with delay.
When I put the lever on out, nothing should happen.

What happens:
When the button is pressed down the dispensers shoots the fireworks with delay, but when the button is released the dispensers with the two and three ticks repeaters shoots a second time.
When the lever is put on on, the dispensers shoots the fireworks with delay, but when I put the lever on out, the dispenspenser with the two and three ticks repeaters shoots a second time.