When I Unsnap a party chat, it insantly boots me from the party and gives me no notification

Same here. Started happening for me a few hours ago but before with 2 people it was fine. Did you get the February update yet? I was thinking that might be it.

Usually there is no need to have the party chat window open while playing. You may just unsnap it. Whether with the Kinect voice command "xbox unsnap" or by going to the main dashboard window, having it unsnapped with the tile "unsnap" and then go back to
the game.

If experiencing problems that chat does not continue after unsnapping the party app, please try to first join and unsnap the party and then start the game.

All notifications go to the notification center (top left corner of Home). If you miss acting on a toast (party invite, friend coming online, etc.) because you're in a match you can wait until it's over, go Home, go to notifications and you can join there,
open their profile etc.

You can actually do what you're talking about using voice though it's a couple more steps and you'll still get some UI over your game...

Here's an example:

You get a party invitation from your friend. When you see the toast say "Xbox, show notification" and then "Launch." This will launch the party app and accept the invitation so all you need to do then is say "Xbox, unsnap." At that point you should be in
a party with your friend.

Another example:

You see your friend come online (starting in April) but you don't have time to act on the toast. You can say "Xbox, invite" which will snap the party app, "Invite friends," (you will get UI over your game unfortunately), find the person in the list and say
"Person 1," and then invite them to a game/chat party. Then you can unsnap the party app again with "Xbox, unsnap" and you're GTG.

Give these a try and let me know how it goes. I really like the suggestion about being able to invite someone directly when you get a toast, I'll take that to the team. Thanks for the feedback!

"Xbox.....snap party" I can now quickly send party invites, go in and out of party chat, see everyone in the party. "Xbox....unsnap".....Easy enough for me. I could care less about achievements, but imagine I can snap it too??

I also have this problem.. hopefully there will be a update soon... erm.. I found this helped with me once.... I UnSnaped the party chat and boom it was fixed