devot:eeDevoted to ExpressionEngine

I am using invitations on a site and it works as expected other than one issue.  All members registered through the DIscussion Forum or Standard Member Registration form are being assigned to the highest number member group.  I have multiple member groups on the site and when someone registers for the discussion forum for example, they are being placed in the wrong group whenever I have invitations enabled.  They should be added to the default group under member preferences.  If I disable invitations, all works as expected.  All settings look fine.  Any idea why? No invitation code is used on any of the forum registration forms.

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