You’ll never fully cut that cord. The energy between you stays. “Moving on” just means you learn to work with that connection differently.
When he pops into your energy field (and he will), you learn to shift from head to heart space. You figure out how to respond to it without losing yourself in it again. Can you become so whole within yourself that their presence in your energy no longer destabilizes you? That’s the work. That’s what separation is actually for.
If they return, they meet a completely different version of you. One with boundaries. One who found the love they were seeking externally, within themselves. I still hold unconditional love for my DM without needing him back. That’s what moving on looks like for me, anyway.