Can F-1 Student on OPT be considered as non-resident for tax purposes after 5th year?

Hi,

 I have been on the F1 visa since August 2013. I completed my undergraduate studies and then began working on the OPT since July 2017. I am currently on the STEM extension. Technically, my 5 years of non-resident for tax purposes ended in 2017, and as of 2018 I would be considered a resident (based on the substantial presence test). However, I see on the IRS website that even after 5 years a student can be considered a non-resident for tax purposes. Can you please help me understand if I fall into this category?

Thanks