Sprite not visible from behind

Hello. So I am working on a 2D/3D project where I have 2D sprites on a 3D background.

Initially I wanted to add a shadow to my sprite (kind of like how you see your shadow on the ground when it's sunny), but the sprite wouldn't cast a shadow with the "Sprite" shader, so I used the "Standard" shader and set the Rendering Mode to Fade, and that seemed to do the trick.

However, the sprite is not visible from the back! If I rotate the sprite 180 degrees, it wouldn't be visible anymore. If I change the scale to a negative value like Scale X: -1, it wouldn't be visible.

I am wondering if there is a way to fix the part where the sprite isn't visible from the back, or if there is a way to make the sprite cast a shadow without changing its shader. Feel free to ask if you need more clarification on anything! Thank you.