Summary:
Activating and deactivating dispensers with a one-block gap next to each other creates a glitched, additional water source.
Steps to Reproduce:
Place three dispensers facing the same way with a one-block gap between each other (and add an additional block in the gaps and five on each side to protect the redstone)
Set up redstone that leads to each dispenser with an optional power source at the end.
Activate and deactivate the redstone causing water to flow out.
Activate it once more causing the water in all dispensers to go back in.
*Optional Step: Cover up water by placing one block in front of the dispenser and two blocks on either side.
Observed Results:
After activating the dispensers for the second time to cause the water to retract back into the dispenser, it seems that an additional water source is created in front of the middle dispenser. Upon checking the middle dispenser's UI, there is a filled water bucket in the slot. Then after covering it up, you need three blocks to get rid of a singular water source.
Expected Results:
After activating the dispensers the second time, ALL water sources should retract into the dispensers and there should be no water in front of any of the dispensers. And to cover up additional water source, it should only be the source block that needs to be replaced, not the flowing water.
Notes:
This bug was discovered in a Bedrock Realm and retested in a test world revealing the same result.
The files attached show the process and the bug that occurs when producing it.
Attachments
Comments 8

This works as expected. Two water sources separated by one empty space (air block) will create another water source in this empty space between them.
This works as expected. Two water sources separated by one empty space (air block) will create another water source in this empty space between them.
This works as expected. Two water sources separated by one empty space (air block) will create another water source in this empty space between them.
That actually is working as expected. By placing water in these spaces, you are creating infinite water sources that are "impossible" to remove by simply using an empty bucket in a dispenser. If, say, you were placing the water so that two blocks of space were between each water source or each dispenser with a water bucket, the additional sources of water would not be made. Simply try to place the water in three spots like you did with the dispensers but without the dispensers, and try to remove the same water you placed. You will see that additional two water sources are made which are "powering" the water source in the middle, making that so it cannot be removed. Closing as WAI.
That actually is working as expected. By placing water in these spaces, you are creating infinite water sources that are "impossible" to remove by simply using an empty bucket in a dispenser. If, say, you were placing the water so that two blocks of space were between each water source or each dispenser with a water bucket, the additional sources of water would not be made. Simply try to place the water in three spots like you did with the dispensers but without the dispensers, and try to remove the same water you placed. You will see that additional two water sources are made which are "powering" the water source in the middle, making that so it cannot be removed. Closing as WAI.
That actually is working as expected. By placing water in these spaces, you are creating infinite water sources that are "impossible" to remove by simply using an empty bucket in a dispenser. If, say, you were placing the water so that two blocks of space were between each water source or each dispenser with a water bucket, the additional sources of water would not be made. Simply try to place the water in three spots like you did with the dispensers but without the dispensers, and try to remove the same water you placed. You will see that additional two water sources are made which are "powering" the water source in the middle, making that so it cannot be removed. Closing as WAI.