I have the same problem and I can't buy house or car and I'm level 8000

It might have to do something with the mod. Can he join lobbies? Also, Rockstar has terrible servers so it might just have to do with that.

I done the character transfer mod I can't join jobs races etc or even buy a house

I think its just rockstar on certain peoples account. I have a non modded account and I have the same problem never can get into a lobby but when the time I do it only has max 3 people in it. And i know its not my connection or nat there both very good. Tried many of ways of doing this and theres no way out of it unless you start up gta go to public and then take out your disk and put it back in. It seems every time I do that I'm good for about a day or two and then back to the same thing can't get into no lobby. Good luck hope you get it to work

Have him do these things:

Clear the reserved space

Unplug his xbox power cable and the router for 30+ seconds

and if he has to, re install the game. He won't lose his multiplayer person but he may lose his single player, not sure.

Never had this issue but try this when Gta is loading press x or square on your controller to where it says loadin online that might work

Dentist wrote Have him do these things:

Clear the reserved space

Unplug his xbox power cable and the router for 30+ seconds

and if he has to, re install the game. He won't lose his multiplayer person but he may lose his single player, not sure.

Have you done this before? Are you sure it works? If so I'm about to do it. I just don't want to wait for GTA to have to reinstall and have to deal with the samething. Im not worried about my single player since I have never even played single player on XB1

Just found something out once your account has been modded , The modder has to go on a race once the account has been modded or else it puts you in private sessions were no one can join and you cant find a new session or .............................. It could be rockstar