Kelp intermittently affected by bone meal

I don't think bonemeal works on kelp.

Do you have a clip of this working?

yes, attached above: working, and not working

I think I'm missing something here in either video they both looked the same and you have a odd point of view.

@Jeremy Rodriguez I also found your videos confusing; I think you may have uploaded the same video twice.

Through testing and using an NBT viewer I have determined that the reason kelp stops responding to bonemeal in a kelp farm is because the kelp block below the one that is broken can be randomly assigned age=25, and Kelp does not grow beyond age=25.

When you break a kelp block that is growing on top of another kelp block, the block below the one broken is assigned a random age. The random age should be from 0 to 24, per the wiki and to match Java. However, the current Bedrock behavior assigns a random age from 0 to 25.

I have uploaded a test world that demonstrates this bug. It contains 8 copies of a bonemeal-fueled kelp farming machine, each placed in a separate chunk for easier examination of chunk data. It also contains a line of command blocks. The command blocks place new kelp blocks in each machine when activated by the stone button. To run each machine, flip the lever on the front. Each machine will run for a different amount of time, but eventually each will stop growing kelp even though the dispenser filled with bonemeal continues to fire. When every machine has stopped growing kelp, examine the chunk data and you will see that all of the single kelp blocks remaining have age=25.

Probably this bug is the result of an attempt to fix MCPE-42575, but the random age assignment was mistakenly coded to be 0-25 instead of 0-24.

Note that in comparison to MCPE-57330, which focuses on natural kelp growth stopping despite age<25 because of missing/incomplete block updates, the farm setup I have used here continuously forces block updates because the piston is fired by the same clock circuit as the dispenser. Because of the bug described by MCPE-57330, the farms in the test world I have uploaded may stop growing for short periods of time and then resume. To verify that the plants all end up at age 25 eventually, you should let the farms run for several minutes after growth appears to stop.

Resolving issues that were marked as fixed in the 1.15 and 1.16 Betas, now that 1.16.0 is being released.