This is an example of a survey capturing SSO respondent data. Notice how the survey flow contains an Authenticator element (blue box). If your survey contains this, please verify the SSO Connection is set correctly (see step 5).
NID http://schemas.xmlsoap.org/ws/2005/05/identity/claims/upn
FName http://schemas.xmlsoap.org/ws/2005/05/identity/claims/givenname
LName http://schemas.xmlsoap.org/ws/2005/05/identity/claims/surname