Reference images (empties) won't stay transparent

I’m trying to model something which requires the use of reference images in the viewport. I chose to use empties in “image” mode for that purpose. I loaded my image in the empty and placed the empty where I wanted it. Then I set its transparency to 0.5. All’s great but here comes the problem. I created a cube mesh object to start modeling and I place it behind the image empty. As soon as I select the cube, the reference image I loaded in the empty becomes opaque! As soon as I deselect the cube, the image empty becomes transparent again. Why is that and how can I make the reference images always stay transparent regardless if I’ve selected an object or not?

Thanks in advance!

Make sure “X-Ray” is checked for the empty:

That’s it! Thanks so much!!!