When looking up at a nearby block, I see a giant mirrored version of that block behind it

Hi there, I'm on the v1.20.1 version I just got here on the server tonight. It looks great but the only problem I've run into is when I'm looking up at a hill or something, there will be a giant version of the block I'm looking at hovering behind it. I also have optifine installed, but nothing else that I think would interfere with rendering.