Regardless what their arrangement is, he's prioritizing her over you. He's making that choice. He lives with his brother, too, so the caretaker responsibilities would be divided between the two. Surely they can come up with a reasonable schedule?

I find it hard to believe he's "unable" to connect with you. I'd also question why a woman would restrict her adult sons' screen time.. and it may not be what you're assuming. Just playing devil's advocate because something feels off.

I'd also question the authenticity of this relationship. If he has a caregiver personality type, it may be he's with you because you remind him of his mother. From his angle, it may be an unhealthy relationship from the start.

At the very least, it sounds troubling for you so a conversation with him could help. Ask him where he sees this relationship in 2 years. What boundaries is he willing to make on your behalf?

If he sounds too perfect for you but is "unavailable", there's something to pay attention to.