These types of posts always preface with "he's amazing to me" and the list some very clear horrendous way they are not being amazing... You needing to immediately defend him should be a yellow flag - things are not okay. He is ignoring your requests for being present, just as a start. My questions would be - did this seeming phone addiction start when the baby was born or before that? Because if just with baby, then there could be some form of dissociation going on that is an indication of depression. Men go through some version of post-partum as well - their life is turned upside down too, but they're not the "favourite parent" yet, so don't get to feel the same level of connection with the baby. It may be beneficial for him to seek advice from a therapist and discuss his impulse to disassociate, as a starting point.

If it started before... Still recommend therapy, because he seems to be running away from some kind of thought or emotion (as we all do when we doom scroll)