If he was never naturalized, he was born an American citizen, thus natural born. If you can produce naturalization documents, then the case is open, but everyone from CATO (who is not anywhere close to lockstep with Cruz) across the spectrum has agreed it’s a non-issue. .
he was born a US AND canadian citizen. he could get passports for both countries day one. he had to CHOOSE which country to align with... which is why he dropped the canadian citizenship recently.