Old Tax Codes "Reappear" after 12.1.3 > 12.2.10 upgrade

Hi -

We recently upgraded from 12.1.3 to 12.2.10. Our 12.1.3 environment had been previously upgraded from 11.5.10 in 2014.

Post upgrade, we have identified that AR invoices for customers in Quebec Canada are not taxing correctly. Digging in, we see that 3 tax formulas which had been in place in 11.5.10 appear to have become "visible" (and active) in 12.2.10. We do not see them in the 12.1.3 environment. There is no way to disable what we believe to be the "bad" tax formula in the ebtax form.

Has anyone else experienced anything like this? We are opening an SR simultaneously to this community question. I am hopeful that the two-pronged approach will get us some guidance. It's becoming more critical every day.