Dog is fine when I leave but completely falls apart when my wife leaves - is this normal?

Otto is a 3-year-old German Shepherd and we have been working on his separation anxiety for about 8 months now. We made a lot of progress with me - he can handle me leaving for 3-4 hours no problem, settles in his bed, barely even checks the camera. Felt like a huge win.

Then we discovered that when my wife leaves without me, it is an entirely different dog. Pacing, whining, won't settle even for 20 minutes. We had not even realized this was happening because we both work from home and usually one of us is here. Found out by accident when I was traveling for work and she tried to go to the grocery store. She came home to a very stressed German Shepherd and a destroyed throw pillow.

Does anyone have experience with a dog who has figured out SA with one person but not another? Does he basically need to go through the whole desensitization process again but with my wife specifically? She is honestly his favorite human in the house so i think that might actually be why - he is more attached to her which makes her departures harder. But i am not sure if we should be training him to her departures specifically or if there is some way to generalize what he already learned with me.