Blocks, Clouds and Banners flickering/showing on top of banners when they are not supposed to.

I have an 'abandoned' area on one of my worlds and I put barriers on top of the walls in that area so people wouldnt escape, but while holding the barrier I realized that I could see scaffolding, vines, ferns, grass (plant), Large fern, Double tallgrass and dead bushes flickering through the barriers, and banners and clouds appear on top of the barriers (it seems much like an issue java had before 21w10a)