party members not getting put into game when host searches and finds game

Xbox (with BF crossplay off for each player) and Xbox+PC (with crossplay on)

This can happen even if I'm playing Solo (ie, i will not make it to my own game). 

It happens seemingly randomly to all party members, though it seems to happen more often to one player.

Excluded player can often join game if they try to join game externally (usually through xbox party), but sometimes even this does not work.

For a very very brief time at the very beginning of season 2, it seemed to go away completely, but came back about a week later.