Can't understand my ex behavior?

I invited my ex to hang out and he couldn't make it but he said we should hang out some other time and I thought we would talk again by the way he said goodbye saying he would keep me posted about stuff... since then we haven't talked or seen each other for almost a month.

However he keeps liking my social media posts (and he's not the type that likes every existing post on social media). Does this has some meaning or is just to remind me of his existence?

I still miss him and think about him everyday but I haven't initiated contact again, I think I've already tried to much...
Can't understand my ex behavior?
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