BQ76972: Some cell voltage acquisition channels are short-circuited, and the acquisition value of the channel should be 0mv, but sometimes 65535mv or 1mv will be read

Part Number: BQ76972

Some channels are shorted without battery connection, and the expected phenomenon is that the voltage of the acquired readout is 0mv. But sometimes these short channels read data as 65535 or as 1.

May I ask what caused this?

uint16 665535= 0XFFFF, plus one will become 0?

Similarly, if the battery is removed from the channel connected to the battery and the channel is disconnected, the voltage collected by the channel is about 647997mv. This is a large value, but it is not 65535 full scale. What is the reason for this?