The though process of circling back

As a person with a FA attachment style I can't tell you, as I don't do that kind of stuff. Not all people fall in the same patterns. Normally when I am done I am done for good, with some up and downs in between. The closest behaviour I could relate to was with my first girlfriend. Lots of fights and drama, I would break up with her after a fight and then she would contact me a few days after (or I would). Miss her a lot, triggered anxious as hell, feeling I was gonna die without her and go back together.

Right!

It's a trauma response. They had unpredictable inconsistency from adult caregivers they needed to stay attached to earlier in life, and they still haven't fully recovered from that today. So they are reactive to whatever is in front if them and disconnected from themselves and can't figure out their own feelings. They've learned in childhood that the people they like and make them feel good and need are also scary and cause pain. Don't get too close or too far. It's a rough way to live, and about them and their past impacting their ability for healthy relating with people they care about, it's not generally about you.

They feel bad too close to you and feel bad too far from you so they react to those feelings by taking action to try the opposite since they don't want to feel bad and figure something is wrong with what they're doing or else they wouldn't feel bad. But they don't know what actions to take to feel better long-term as it's not actually about the romantic partner. Hence FA being disorganized attachment, no organized strategy for getting needs met, just flailing around.

Edit: description is for unaware FA, and they're more likely to return for the chase for this reason if they have a tendency to lean into their anxious side.