Why my Eevee material with Alpha won’t show correctly I have 2 objects: 
1. An imported Image as Plane (2D).
2. And a simple 3d object.
I was following the advice in this video.

The Alpha is working fine for #1, but not for #2. They are using the exact same nodes though. Both have their Blend Mode as Alpha Blend.

The Alpha may be working for #2, but its texture got all screwed up. I thought it was just a mater of fiddling with the Normals, but that didn't help :frowning:

What could be the solution then?

Feel free to play with the .blend file attached herein.
https://blenderartists.org/uploads/default/original/4X/2/1/0/210127fbbbc80c006ad8bd33fe25be210d0d6490.blend

Thanks guys!
2 Solutions were found. 
#1 by Benny_G: Instead of using Alpha Blend for the Blend mode, use Alpha Hashed.
#2 by NewVisitor: Use the Principled Shader instead of the Diffuse BSDF Shader, plugging Alpha to Alpha from the Image node to the Principled Shader.

What caused the need for this fix, it's still unknown.