Communication Issues??

I feel like my boyfriend (of around 5 months) doesn't listen to me, or maybe doesnt remember or see it as a big deal or maybe I'm over reacting but I told him when we get on the phone I just want us to be doing that, just talking to each other. We rarely talk as much as we used to and now its mostly just a few texts during the day and maybe a call or 2 as well but always a call at night before going to bed which can be from 10 mins to 2 hours depending.

Now since we barely talk during the day, like I said earlier, I have communicated to him that when we get on the phone I would like for him not to be going on Instagram or snapchat, etc and to be solely into the conversation. I say this because there have been times where we are on the phone in silence because he is absorbed into a video on instagram. And just recently it was a 10+ minute long video on youtube.. I have mentioned this to him at least 3 times and once again tonight I saw that he was on while we were on the phone and it upset me because I was enjoying the conversation but now I feel like he may not have been or wasn't paying attention fully.

Am I over reacting? Should I keep mentioning it or just drop it? Any tips?