Okay...who is the alpha...mom? Dad? Whoever is the alpha should STAGE their leaving the house: Good! Potty, crate/or room, but Alpha's shirt/housecoat/pillow etc., for pup to help with anxiety.
We left for 15 minutes...then 30...then an hour then two, and so on. Each return was with "Joy."
When I went back to work, it was potty, treat, love, housecoat on floor, hugs and joy; repeat! Repeat and Repeat and Repeat. Change the time frame...slowly, and reassure the pup that mom/dad always come home.
Anyone who FEELS the dog should just adapt without coaching is...well, ... you know.
Dogs are trained and learn fearlessness by being reassured that all is well. It takes time, but a mentally healthy dog is worth the effort.
I treated Bailey like my child and taught her to be accepting of her world...not fearless of it, just, reasonably non-reactive.
"Alone" is not the same as being abandonned, it is a trained response, over time, practice,,,practice...practice. If it is obvious that Mom always comes home, and "that reality" is drilled and repeated, over and over, then the anxiety is diminished. You give your dog the tools to survive your time out of the house.
It is a slow marathon training your dog, not a sprint. Good luck. EMPATHY, EMPATHY, EMPATHY.....And, payday!