Ex boyfriend being weird about Mothers day

So my "ex" and I separated about 2 weeks ago. Since then he has been all about "co parenting" but then shows up late and doesn't take my calls. There was a situation 2 days ago where our 9 month old ran out of teething medicine and that evening we had an argument so he left and he was supposed to come back but didn't. I called and called and texted and texted to no response. I had to call him on my grandpas phone to get ahold of him. When he answered and I told him what was up(he was with his mom) I heard his mom in the background and then he hung up on me. He brought his medicine at around 12 at night when I called him 7-8pm and even though our baby was already asleep.

When he comes to see our baby it's quite literally only to see him and he doesn't talk to me unless it has to so with what I'm making for dinner and our baby. It's infuriating because we both agreed to separated and do couples therapy and try to help the situation but he's always like "I don't want to help the situation." We can't just leave it high and dry like this especially because we have a child. Our son has already picked up the way his father treats me and it breaks my heart. I'm trying to do everything I can to help the situation but he's just being so stubborn and conceited.

Anyway back to Mother's day. Yesterday was Mexican Mothers day to which he sent a text congratulating me. I thought that was nice because the past couple days he's been awful. When he comes over in the evening he brings up getting me a gift and makes it clear that it's because I'm our sons mom. Now my question is this: What is homie planning? Because he buys me dinner, helps me with things relating to the baby and not relating, when we're having baby time together it's like he never left. He is constantly doing things that give me mixed signals. Even yesterday he said he wanted to go to a sit down restaurant. He offered going to Lucille's which is a very expensive restaurant especially for what we make. He's being weird about it. I don't know what to think because what he's telling me and what he's doing contracts each other. Maybe I'm just reading too much into it idk.