Notifications were missing for a while last time before correcting, now it has only been a ~week. They are haphazard, some make it through. But most of the time I will see completion messages without the ‘trade accepted’ message that caused it. i.e. “You hit all Very Rares for blank” but no “blank has accepted your trade.” It isn’t listed as read either, I can’t find the message in the notifications list.
I will make sure to e-mail support, thank you Joe.