Steps to reproduce the bug:
1) place down 5 redstone repeaters in a row, each one pointing in the next one with a delay of 1 and lock them.
2) input this sequence into the rightmost (rightmost if you build the circuit as i did) 3 repeaters: on-off-on.
3) unlock the row of repeaters for 1 tick (you can unlock the repeaters for more ticks but you will need more repeter at the front), then the bug should happen.

What I expect to happen:
the sequence should have propagated without changing order and/or state.

What actually happens:
Seems that the repeaters in the on state last longer than the off state causing the repeater to not change state in time and the off state to vanish.

The last pic show all the sequences that i have tested using more repeaters; the affected ones are those marked with a redstone block, they all share the characteristic of having an "off" state between two "on" state.