Multiplayer issues on kids account (already changed settings to allow multiplayer and allow...

I have tried just about everything I can think of and things I’ve researched. My son and I just set up his Xbox two days ago. Setup was a breeze with no issues….UNTIL he attempted to play multiplayer with his cousin. No matter the game, it told us this account is not allowed to access multiplayer. He has 3 months of Game Pass paid for. At first I thought this was an easy fix. As all I thought was needed was to change the family and privacy settings through my parent account to “allow” for all multiplayer game related settings. They were already in the allow positions but I undid them, saved, then turned them back to allow, saved. I power reset the Xbox, including taking out the power cord for a few minutes then powering it back on. Then I thought that it might be my nephews settings (his cousin) so we checked his as well and it was all good to go. Not to mention he plays with other friends no problem, but I thought it was worth a look. At this point I was frustrated as all hell. So I decided to just buy $1 first month of game pass for my (parent) account so he could use mine. Ran into the exact same problem. I get the feeling that I’m missing something infuriatingly simple, but I hope that is the case. I thought about just resetting his account and starting over but that would mean his 3 months of game pass would be lost. Please help! I’m about to pull my hair out lol.

:)