you said you tried everything so maybe you did. but it’s unclear.
have you tried setting the filter to nearest?
it’s under advanced, which is not expanded in your video.
also the texture is very big, i wouldn’t expect it to look good at such a tiny resolution. i would really consider reducing it.
also the engine might have the rendering resolution lowered in the scalability settings (this is only for the viewport is not something you really need to change, and will also impact the performance while you work).