https://drive.google.com/drive/folders/1vyW-nTrIoCDKJ7Ai1asSM35qrb1zmoK_?usp=sharing

From the first video in the folder (Current Minecraft Java version), you can see that on Java the kelps growth can be detected past its initial placement. This is incredibly useful.

From the second video in the folder (Current Bedrock edition version), you can see that the kelp doesn't get detected past its initial placement. This hinders a hand full of farms utilizing kelp.

The file name of the videos are labeled the version of the game just incase. I also noticed while watching the videos back that Kelp doesn't have the same placing noise (but that's not important).