When do avoidant’s come back?

*not looking for advice telling me to move on*

My avoidant ex (30s) broke up with me (20s) 3 months ago out of no where. No real explanation, no discussion. Recently, my friends have run into my ex and my ex has said hi to them first. I don’t know if that means anything… my ex really never goes out of their way to say hello to someone first. Haven’t spoken since the break up. I do think of them often. I want them back sometimes, we were together for a couple of years.

Do they ever come back? If they do… when? If I were to reach out first, when would the right time be (like after how many months?)