"You have an interesting vehicle."

Tu tienes un vehiculo interestante should be a correct answer, but returned an error.

Why is "Tiene un vehiculo interesante" not a right solution, Tiene is a usted form of you and should be accepted.

Why is, "Tu tienes un vehiculo interesante" wrong?

Posees? Out of the blue posees?

There is no indication of person. Tiene, tienes and tienen are possibilities

Tiene un vehiculo interesante ==> why is it wrong?

why is usted tiene wrong ???

Once again, if YOU is the subject, Duolingo needs to define which YOU. Usted, Tú, Vosotros, Ustedes....????