The My Snipes screen is not very intuitive!
The correct procedure is to create the group as a bid group and add the items. Or set up the items, create the group (as a bidgroup) and move them into it. That said, as soon as you do that they'll disappear unless you Choose FolderAll Snipes (top left of the My Snipes Screen).
So wait a bit then try again. Or click on the Help Tab and send in a support request.
R2