I have spent the last 3 days trying to figure my tax requirement with no luck. I called CRA and the person was not sure, and my accountant seems clueless as well, I could really appreciate your input.
I arrived to Canada as an international student:
2012 – 2018: I was on a work visa as I work in the medical field, but I was also on a scholarship, and basically my income and tuition were paid fully by my government. I received deposits in my Canadian’s bank account ( scholarship allowance) , and my country’s bank account ( my salary as I was sent from a company for training ) during that time. I was under the impression that i did not need to file tax back then.
in 2018, I got my PR while still on my scholarship. I went to H&R to file for my tax that year, and they said that my income should be 0 as I am here on a scholarship, and did not receive any income from Canada since my money came from my government.
in 2019, I got a job in Canada, and now i am preparing to submit my tax.
I hired an accountant this time, and he notified me that I need to file for taxes from 2012- 2018 and I may owe me as well.
During 2012-2018, I stayed in a rented apartment, I was single, no children. I did have a Canadian bank account, a Canadian driving license and OHIP.
My scholarship was generous, and I was able to save a huge amount of it, and I had more than 100K saved in my account after 5 years on that scholarship. My accountant said that I owe money because its more than 100K, even though I was on a scholarship.

I really will appreciate it your input and guidance
Thank you