Parents and children argue, but I wonder why his mother didn't want to report to police he was missing. Maybe she thought they (the friends she called) could help find him, he would turn up, and she didn't want to risk losing custody?
Maybe she was in denial that it was time to call police.
Just trying to speculate on innocent reasons.
Not involving police quickly goes against recommendations when a child is missing, but a lot of families do search on their own first.
I am concerned about the RSOs, or any not registered, living nearby. If Xavior was outside a lot, maybe he was approached / groomed by someone in the neighborhood.