Connection

I’am having a big issue related to my connection and I’ve been calling Microsoft and xbox box for the last pass couple week.
I’ve change my tager names twice and since that change I cannot log with my friends simmer any more
Their sending me a invitations and it does’nt work so I went back for a third time with my first tager name Basile1p and I still cannnot connect with my friend.
I’ve deinstall the flight last sunday and reinstall it the same day and NO it not working.