Can someone please address the issue as to why I keep crashing when loading into a game?

When loading as a partner to the leader of my squad I frequently crash during unit selection. It will show me that there is one opponent and one AI Commander, 5-8 secs after I enter my game freezes and my partner is sent into game with an AI, messing up the chances of winning. Why does this happen so often and what can be done to fix the issue?

Thanks

This is happening all the time now and is really messing things up. My partner always has to evac or quit when he joins because the AI is no good.

Why is this being caused?