Yes, there are many "secondary addictions" for those with altered brain chemistry and depressed receptors from years of drinking. Relationships, shopping, gambling, porn, even exercise. Anything that brings the dopamine and brain chemistry back into balance. I was notorious for buying new cars 30 or 60 days into sobriety when I was younger. I would be so bored, and seeking a rush, apparently.
The relationship situation also happened to me when I was overseas and almost a year sober. I didn't even realize that it was my addictive brain seeking a substitute - I was just happy for a new girlfriend, exciting times and adventures.. and amazed that I wasn't drinking. I actually moved over there for a few years, then made regular trips back and forth until the pandemic stopped that. But after a few years sober the stress of the crazy lifestyle and my complacency brought me down and I picked up again.
It took me a long time to figure out that I had substituted an addictive relationship for an addictive substance, and as part of that realization - that I had major codependency and attachment issues that go back to my childhood. And lots of emotional pain, which made it difficult to break off, and which has been a major reason I drank over the years. Basically it opened up complications that I am still dealing with, but I wouldn't trade the experience for anything - it really changed my life and served as a catalyst for further awareness.