We have had a couple of people report a similar issue to this one before. We believe it was due to the user using the enter key to close pop up boxes following the cocnclusion of a Heads up Sit & Go tournament.
Please have a look at the these threads here and here to see if this solves your issue.
If not please do leave further feedback and we will investigate this in more detail if you can leave us more inormation on how it happened.
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