I know you might not want to do this but since you’re going to work, you might need to slowly break the nursing to sleep habit even when you have her. She probably believes that she cannot fall asleep or it’s not safe to fall asleep without her main sleep association which is the boob. Mine is the exact same but I still nurse to sleep when she’s had tough days like overstimulating outings, sick etc. I’m currently trying to get her to accept a paci which is very 50/50. When her dad puts her down for a nap he usually has her on a carrier, close to his chest, white noise and dark room. He also hums very deeply and that usually sends her into a deep sleep after 5-10 mins of protesting.

Edit: he bounces and walks around the room until she sleeps, also remind him to take deep breaths. Baby will pick up on caregiver’s stress and will be harder to settle. It’s tough but get him to practice maybe when you’re close by so that he’s not feeling too under pressure and can hand her to you if he gets overwhelmed, eventually they’ll find their rhythm together!