ULN2003A: ULN2003A damage in usage

It is a failure issue in ULN2003A, ULN2003 has been used in similar design on many projects, but the failure happens in 3 prototype boards with total 10 prototype boards.

in the past usage, the c pins are all pulled up with 15V, the pull up resistor is >1Kohm, but in this design, both 5C and 6C are pulled up with 5V while 1C~4C are

pulled up with 15V.  the COM pin is directly connected with 15V without any resistor.

the 3 ULN2003A chips are damaged in different 3 prototype boards, but after replace the damaged chip with new chip, the failure doesn't happen again.

the date code for these chips is 76C2XSK, local CQE has checked that there is no similar failure in the products with same date code.

Local team suggests to add 1Kohm resistor between COM pin and 15V.

for the root cause, could you give your comments or analysis?

thanks.

Below table is the pin impedance comparing between good chip and damaged chip.