Window (glass) not casting shadows

Hi! I encountered a small problem with casting shadows from a glass like material. I get no shadows from it and no light can pass through it. I tried to figure out why this happens on a simple geometry but with no success. I have a BSDF set for it in blender and the Blend mode is set to Alpha Blend and i am also applying a THREE.MeshPhysicalMaterial after importing it in three.js. What am i missing? Is there something wrong with the blender file?
simple.glb (6.1 KB)

Um, according to your screenshot the window does cast shadow. Notice that transparent objects produce the same shadow darkness in three.js compared to opaque objects. Related topic at GitHub: