Lately, I have been experimenting with minecraft TNT cannons, and have recently stumbled upon an inexplicable issue which I can only classify as a bug. The redstone behavior when powering dispensers happens to be inconsistent and faulty, as for no apparent reason, certain dispensers (although receiving a power source) will consistently fail to fire. As you can imagine this is rather annoying because it prevents my cannons from properly functioning.

I know this is an issue with Minecraft, and not just a building error, because the dispenser will work properly for the first two times it receives a redstone signal; when the cannon is fired. Afterwards, it ceases to function while all the other dispensers (which are powered with exactly the same current) continue to do so. Furthermore, the dispenser opposite from the faulty one functions properly.

Additionally, this has happened on more than one of my cannons. It actually has actually occurred on three of them, and seems to be prevalent on those that stack dispensers on top of each other, which you will see in the screenshots I have provided. In these I have also indicated which dispenser fails to fire on two different cannons, and the dispenser opposite from it which does not fail to fire.

I have explored other possibilities, but was unable to find a solution. Therefore I can only assume this occurs as the result of a coding error in the game.