75200 over voltage fault with 80100 outrunner

I have a small issue with my 75200. I try to set it up with 80100 outrunner, but each time I get an overvoltage fault. I have a 20s 55 Ah battery. I changed the overvoltage limits from 6V to 85V, I wrote changes, and after trying to set up my motor again, I still got overvoltage, and when I returned to the limits section, I saw that it went back to 6V. Thanks in advance for your help.