Minecraft Forge 1.16.3 (34.1.5+) with Optifine

This won't happen in most places, only in this city, where all lines were replaced by the lines from this mod.
As soon as I left the city far enough, everything goes back to normal.

This didn't cause any error or crash. I'm assuming it's an issue with texture or Optifine. Only in this city where an enormous amount of pavement lines was used had this problem. While we started replacing vanilla textures and filling these lines, it didn't happen at all until recent days when we completed a full replacement across the entire city.

I tried changing settings in shaders and optifine, nothing worked out.

This may be a bug of the shaders. Try reporting it to OptiFine or the shader creators.

Does this happen without shaders?