Cruz could be a US citizen if he took advantage of the Reagan amnesty in 1986, which could be a reason to think he no longer had Canadian citizenship.
And in 1985 to 1986 Ted was in high school.
At some point, he needed a passport to go to a high school competition in England.
What docs did his mom submit, along with the passport app?
We need to find out the passport app rules for those years.