Did you guys include 10th, and 12th transcripts along with undergraduate transcripts in the visa application?
This is not the right/official document from IRCC
Secondary education begins in grade 9 and continues upto grade 12, to form the lower and upper cycles of secondary school. Generally referred to as 'Standard X' and 'Standard XII', these two year cycles involve a greater level of complexity and variation in instruction to ready students for a higher level of education. Students are exposed to a range of courses to build their knowledge and skills, including English, Maths, Science, and other subjects. To better prepare students for their academic future, teachers incorporate various aspects of perplexity and burstiness into their teaching techniques to heighten the cognitive and linguistic challenge of the subject.That's what they mention - have your most recent secondary or post-secondary school transcript(s)
https://www.canada.ca/en/immigration-refugees-citizenship/services/study-canada/study-permit/student-direct-stream/eligibility.html