As the video shows, when the player is in the water, the border of the slime blocks is no longer rendered, and I can't reproduce the bug in Minecraft 1.21.1, so I guess it's a regression from the latest version of Minecraft.
As the video shows, when the player is in the water, the border of the slime blocks is no longer rendered, and I can't reproduce the bug in Minecraft 1.21.1, so I guess it's a regression from the latest version of Minecraft.
Relates to MC-277772, also rendering that broke in 1.21.2.