I am not familiar with Canadian tax rules so I cannot help you there. Sorry.
I am not giving you tax advice re the substantial presence test, but here is the computation that seems correct to me:
Assuming you spent the entire 2019 and 2020 in the US, and no 2021 days in the US:
2019 = 365 x 1/6 = 60.83
2020 = 366 x 1/3 = 122.00
2021 = 0 x 1= 0
Total 182.83 which is less than 183.
Again, I am not giving advice. If you see any merit in my computation, check it out.
