Max's brain processes visual cues differently to other teenagers, which make it difficult to keep up with lessons requiring rapid transition from whiteboard to workbook. He wears glasses to counteract the way he perceives light, which includes hyper-sensitivity to the type of fluorescent lights typically found in classrooms.

His mum Jennifer recognised early that her toddler didn't always behave in ways which were typical for young children. They discovered through consultation with a psychologist that Max had autism.

She said schools face a "significant challenge" when it comes to students who learn differently, like Max, stressing St John did what it could to prevent his decision to leave last year.

"No matter how good they are, it's hard for them. It's a huge ask for a school to cater to every student's different needs," Mrs Lyddiard said.

When Max's perceived academic failing lead to a rapid decline in his mental health, his parents acted quickly to enroll him into the Canberra Institute of Technology, where his love of music would enable him to gain his high-school diploma and pursue his real love; baseball.

Since Max was six he has excelled at the sport. His selection for a high-performance team, which trains six times a week under the guidance of the Canberra Cavalry, has pushed him closer towards a US college scholarship as a pathway into the big leagues.

As a year 10 student at St John, Max participated in the School Sport Australia competition which sees the best athletes from each state selected to take part.

Despite being selected again this year, Max was disqualified from the competition because he is no longer enrolled in a mainstream school.

Mrs Lyddiard said the week-long competition has the potential to make young athletes' careers, as talent scouts are often in the audience.

Her youngest son Ryan is still enrolled at St John and has been given the green light to attend.

"They're two years apart," she said. "There's been so many situations where we've had to do things differently. To get to the point where he's almost an adult and to still come up against this. It's kind of defeating that we're still having this conversation." Max is one of around 300 students completing their high-school certificate at CIT who was told, alongside University of Canberra HSC students and home-schooled students in the ACT, he was excluded from the national competition because the institutions are not affiliated with the territory's education department.

A spokesperson for School Sport Australia said it was the education department's decision for which institutions were affiliated with them.

Having contacted the minister for sport and been met with refusal from the ACT branch of school sports, it was only after the Sunday Canberra Times approached the ACT Education Directorate that Mrs Lyddiard was contacted.

Mrs Lyddiard was advised last week that through his music program, Max could register as a year 12 student at CIT as it was affiliated with the program. Despite the fact year 11 at CIT wasn't, Mrs Lyddiard rushed to fill out the paperwork required.

This week, the family's hopes were dashed when School Sport Australia contacted them to say they'd been misinformed.

"Max is pretty gutted. I'm still pretty optimistic that something can be done," Ms Lyddiard said on Thursday.

The ACT Education Directorate did not respond to the question of where this confusion had stemmed from.

"The Education Directorate is working with the family involved to ensure the best possible outcome is achieved," a spokesperson said.