In the new snapshot, we fixed the generation of grass above the water and because of this, the seeds of this grass float in the water in the form of a drop. This can be very stressful for the world.
Reproduce
Seed: 7622494782975431164
Coordinates: /tp @s -1200 63 -904
this is because flower generation happens before water lake generation if this is fixed the whole way minecraft generates would need to be redone