If you did not get Shuffl'd into a group then verify the following:
Verify that you are still a member of the shuffl Slack Channel.
There is a small chance you might have been matched with the exact same people as a previous match. In this case, the private group message will already exist and you should see a new notification within Slack. (or it may be hidden if you have muted that DM group thread)
If you are still having issues, please contact firstname.lastname@example.org - we're happy to help!