3820586 - New Concur Travel - Error: "One or More Required Fields are Missing from Your Profile" when Booking Rail

I am booking Rail via Trainline or Renfe on Concur Travel and receive the error "One or More Required Fields are Missing from Your Profile" on the Review & Book page. The Gender and/or Passport fields are not visually marked as required on my profile.

When booking Rail via Trainline or Renfe on Concur Travel, the error "One or More Required Fields are Missing from Your Profile" appears on the Review & Book page. The Gender or Passport fields may be the cause depending on the company's TSA Secure Flight and Passport configuration, one or both fields may be required at booking even when not visually labeled as required on the profile screen. , KBA , CON-CA-USP , User Profile , Problem