I am building a line of 16 dispensers, attempting to activate the first with a specific setup while a line of 15 redstone dust powers the rest. The setup I am using is shown below in "Setup_one.png", though this issue also occurs with the arrangement shown in "Setup_two.png" (only difference being the dust behind the dispenser being removed). The first time the repeater is powered, all 16 dispensers drop water as expected (as shown in "Activates_First_Time.png"), though subsequent activations fail to power the first dispenser (or at least to dispense the bucket - as shown in "No_Longer_Activates.png").

I also tried replacing the dispensers with pistons to test if this was a powering issue, and the piston in place of the first dispenser did continue to extend with subsequent activations. It could have something to do with quasi-connectivity or something? (I have never understood quasi-connectivity and never will, so I have no idea)

Steps to reproduce:

1. Create setup shown in "Setup_one.png" (only first two dispensers are necessary to reproduce the issue)
2. Power the repeater, such as with the lever shown
3. Unpower the repeater by switching the lever off
4. Power the repeater again by switching the lever on

Expecterd result:

1. Water is dispensed from all dispensers
2. Water is picked up by all dispensers

OR

1. Water is dispensed by all but the first dispenser
2. Water is picked up by all but the first dispenser

Actual result:

1. Water is dispensed by all dispensers
2. Water is picked up by all but the first dispenser

Additional information:

Repeated activations will not cause the first dispenser to pick up its water, so the source block it first dispensed will remain there forever. However, I did find that this can be reset by removing the redstone dust (shown in "figure_1.png") and then putting it back (shown in "figure_2.png"). It will then allow the dispenser to activate once (shown in "figure_3.png") but will not cause it to be activated any more times afterward.

By removing the line of dust that powers the rest of the dispensers (shown in "figure_4.png"), the first and second dispensers will be able to activate every time the repeater is powered (shown in "figure_5.png" and "figure_6.png"), suggesting that this redstone line has something to do with the issue.

Additionally, while it seems this result can be replicated with both of the setups shown in "Setup_one.png" and "Setup_two.png", the first time the dispensers are activated in Setup_two, the first dispenser will activate at a short delay to the other 15. The interesting part about this is that I had assumed the first dispenser would not activate at all in this setup.