Same here, M2-700 Wh, 67 cycles, due to removal of magnetic particle from port caused failure, shortcut of pins. 3rd led blinking during charging. I am from EU.
I have the same problem with my m2-700 Wh MY21, 3rd blinking green led while charging. Battery had only 67 charge cycles until a smal magnetic iron part on the charging ports caused this failure during removal.
Since then cells were unbalanced. Tried to balance the cells at battery repair...