Ex-opiate addicts avoid sleep to obtain a nod

Me and my SO are both recovering opiate addicts. Major fentanyl users who have managed to abstain for >4 years now. I was curious if any recovering opiate addicts have had experience with the following: my SO avoids sleeping like the plague - it leads her to often nod out almost similarly to like we used to when we were actively using. Important note: she is not using and I am 100% positive of that.

The main reason I’m posting this is cause I’m curious if any recovering addicts have ever had a similar urge to do this. I personally love sleep and am an early riser. She is a night owl, but over the years it has gotten worse and worse. Nowadays I wake up at 4-5am to start my work day and she’s still awake and doom scrolling or nodding in the bathroom and getting to bed around 5-6am. I have to wake her up at 7am usually for reasons I won’t get into, but you can likely guess and then she’ll usually go back to “sleep-ish” (sleeping at the table, in the bathroom, etc) or sometimes will go to bed and then I wake her up again at 2-3pm.

Any input on a shared experience is appreciated, but please note: she is not using and that is something I am 100% sure of. My thoughts have been that this is some type of mental health issue. She speaks with therapists and psychiatrists but they have no valuable solution or input.