Repeater's tick doesn't work correctly.

Repeater's tick doesn't work correctly sometimes a repeater with one tick and redstone line only (redstone line is only have 0 tick) has the same speed. Look at the screenshot below the piston extender, sometimes it work correctly sometimes not because a ticks is changing it's speed. That two repeaters sometimes it's speed is same as 1 repeater with 4 ticks. Please fix this ticks is very important.