Floating Grass/Tall Grass above water

Put the summary of the bug you're having here

What I expected to happen was...:
It was just something I came across

What actually happened was...:
I came across some grass and tall grass just floating over the water with no grass block underneath it

Steps to Reproduce:
1. Again, I just came across it
2. The first time I saw it I thought it was just the way the world generated just like you get sand caves that collapse when you place/break a block near the sand
3. The second time I saw it I wanted to report it just in case the location of the two were far away from each other...

I'll add some screenshots of one of the two I found I couldn't find the other one to take screenshots of too.

this is about three hours later of looking around my world and I saw a few more similar to the other two I've found if this is just very bad luck on a world generation then I dunno what to say :| I am giving this a category of Unassigned because this is the first ever bug I've found in the game so... yeah i dunno what I am doing and sorry if this is too long...

Also I just noticed some grass on the sand :|

the only other way I know to verify is to like give the world seed and coordinates to where I found the stuff

sorry if there is something like this out there already I couldnt find it and I dont know how to work this stuff I haven't had to do something like this before

seed: -6342650400429430990

spots: -125.07 64.00 1248.02         -126.89 63.00 1206.12