The only way of knowing if a cell group hits HVC before any others is to charge as far as poss then open the battery to get all 10 cell group voltages to see if a problem does lay there.
You should always measure the cell voltages from the common ground. That will tell you where your missing voltage is.but one thing I’ve noticed as it’s 36v should it not have 10 cell groups (10s) and thus should there not be 11 wires on the balance plug mine only has 9 wires??
cheers
Thick black joined to the cell-pack. Not the black joined to the battery terminal because it's switched by the BMS.Common ground ?