So I found out what the issue is I think...

I had the opposite happen to me, I was logged in when I sold a player, and he didn't move right away when he sold (in the fourth round! booyah!). After refreshing my frame I got the full-screen notification that he had sold along with the "email".

So I'm guessing that if the selling manager is logged in there's some kind of lock on his players so that the programmers didn't need to write an event handler to force an internal refresh of your team.