As long as the account is open, it will reamin on your CR. Negative info will go away in 7 years but good information on an account can stay on for 10 years. If the account from 85 was closed, then it just probably dropped off 10 years after it closed.
It also may be possbile that your EQ file "split". I have seen posts about this here before but I dont have any experience with it myself. I would call the EQ poeple to have them verify your credit report ASP.
1/25/2021: FICO 850 EQ 848 TU 847 EX