2 things spring to mind:
Your accounts arn't linked by any chance?
Is either account a child account?
When playing Fortnite on my xbox 1S with my daughter on Switch, recently i seem to get kicked at that match point too. It was more prevalent when she joined my party (not sure if it was invite or non invite here) or the odd time when I joined hers, non invite. Now I join her party from an invite and we dont get the issue. I made no other changes to my settings.
Dont know if that will help in Apex, but have you tried the different join lobbies and invites to see if theres any improvement.
