One of the battery is not detected.

I have made one 6s1p pack to perform test on ENNOID BMS using Master-05/2019 and slave LT6811-05/2018. The issue I'm facing from last one month is whenever i connect 6s or 7s or any configuration Software shows -1 cell in its Real time data window. I tried to debug hardware i didn't find any issues as of now.