kelp has growth problems breaking some farms

i was making a kelp farm that was 20 blocks high for unlimited fuel, then the kelp would get stuck and i would have to break the top block for it to grow, sometimes it would grow 40 blocks high in the water testing tube, sometimes only five, and even sometimes would refuse to grow past 2 blocks.

so i remake the farm with a more complex mechinism so its only 5 blocks tall and the kelp still gets “caught”. it is compleatly random what will break it.

i am submetting this because it seems buggy that kelp cannot grow more than 2 blocks for no reason.