They may be set to vram compressed, try vram uncompressed. Per-resource Import settings can be found by selecting the texture and selecting the “Import” tab, usually beside the scene tab
if it’s set to vram compressed, don’t set it to uncompressed, just go to import and enable high quality, that could be what is causing the artifacts. vram compressed is the best combination of good quality and performance.
you can also disable mipmaps, this is a very small image. but since it’s a very small image it’s unlikely mipmaps is even doing anything.
the other thing that is different is the texture filter, this is set per material in StandardMaterial3D, or per sampler2D in a custom shader.
linear makes it look blurry, while the nearest option is for pixelart and will make the pixels sharp. for best quality when looked at from an angle, you can also use the anisotropic filter option.