strange attitude from my ex

I really want to figure out some things and i would love to hear an opinion from you. Back in january my ex broke up with me and we went no contact until this month. He texted me for my birthday and to tell me about his exam. We talked for some days about my holiday. Since 3 weeks ago ( when he broke no contact) he has been sending me messages almost everyday , but the problem is how he does . Every two or three days he keeps answering to my WhatsApp stories , even when he shouldn’t or there’s no reason to do . For example yesterday I posted a story of an edit where the person has to choose two doors and he chooses the door saying that he wabts to be silent .. he replied with a random sticker . Another day I posted the song “talking to the moon” by Bruno mars and he replied with “f*** u”, other day I posted a pic about myself and he replied with “no” .
Not gonna lie , I still have feelings for him so that’s why I want to understand his intentions. To me it looks like he is scared to get in no contact again so he answers every story of mine just to have a little random conversation everyday.. but why chasing someone you don’t love? So yeah I am kinda confused and idk if that’s starting to disturb me or not. By men psychology what does it meannnn