IRS Publication 936 for the 2020 tax year is still "in review" by the IRS. Therefore I"m not using that version. I'm using IRS Pub 936 for 2019 which you can see at https://www.irs.gov/pub/irs-prior/p936--2019.pdf
Now if I go page 10, Grandfathered Debt, from what I read that section doesn't apply to you at all since the original mortgage you refinanced was not taken out prior to Oct 14, 1987. As I see it, the limits apply to you.
