You already know. That is the honest answer, and sitting with it is harder than asking the question.
The pattern you are describing tells a clear story. Repeated parole violations, unexplained absences that last a full night, no contact until the next day, and a cycle of going in and coming back out. Each of those pieces on its own could have an innocent explanation. Together they form a picture that has one most likely cause, and you know what it is.
The sweetness and the love are real. That is not in question. Addiction does not erase who someone is. It competes with who they are, and sometimes it wins. A person can be genuinely caring and loving and still be in the grip of something that overrides their best intentions on a regular basis. Both things are true at the same time.
The harder truth is the one the original answer states plainly. You cannot want his recovery more than he wants it. That dynamic does not work and it does not end well for either person involved. People change when they decide they are done, not when someone who loves them decides it for them. Until that decision comes from inside him, the cycle you are describing will continue on its own timetable regardless of how much you care or how closely you watch for the signs.
What you can control is what you are willing to accept as a condition of staying in this relationship, and what boundaries you are prepared to hold. Those are worth thinking about clearly, not as threats or ultimatums, but as honest questions about what your own life looks like if nothing changes.