Dating and then ghosted (mostly but not 100%).

I’m confused. This guy pursued me and we hit it off quickly. A lot in common, great chemistry, etc. He came on pretty strong and after a month things got physical and he basically ghosted not long after. He and I are both divorced and he mentioned his last girlfriend was a year ago and it lasted for about six months. He told me about her and she had some big issues (still lived with parents, past addiction issues, legal issues because of it etc.). I also saw a picture and I felt I was more attractive and didn’t have any of the same issues. So I’m super confused. He is comfortable with relationships. If he was just interested in sex ( initially I told him I wanted to wait and he was ok with it….clearly I gave in), then why do that with someone that could have been a legitimate relationship? I can usually sense when a guy is only interested in sex and this guy didn’t give me that vibe. It was like once I stopped being hesitant and felt like he was a serious possible partner though,he fell off the face of the earth.