He keeps blocking me if I take too long to respond

so this is actually my ex he’s 22 I’m 21 we’ve been on and off for 4 years yesterday would have been our 4 years but we broke it off in the beginning of this year but regardless we chose to hang out last night we talked, we had a good time we did it, well prior to us hanging out yesterday we’ve been texting for a couple months here and there and he blocks me when I don’t respond fast enough like what even is that? 💀 he texted me this morning I’m hung over trying to sleep in and when I go to text him back boom he blocks me again like idk why he acts that way he says there’s something wrong with his phone but I don’t believe him😂 also y’all can be honest I’m really getting over this guy anyway so give me your honest opinions. Maybe he just wanted to f****? lol