The product allows you to make changes to search lists, but this doesn't always mean that this replacement takes into account specific required record types.  This is what's happening in this scenario.  To be a prospect team member the constituent must have a constituency of fundraiser.  When using the constituent search screen here, in place of the fundraiser search, it pulls non-fundraiser records into the search results instead of just fundraisers (which is the purpose of the fundraiser search).

To resolve we'll have to remove this search list replacement in administration with the following steps:

1. Go to administration functional area, Search List Replacements
2. Delete the entry for Fundraiser search under the constituent area
3. Log out or Refresh the application and attempt to add new team members