Pb GMR Board

I ordered a V1.1 GMR Board (DFR0271) to control the robot HCR.
Nano 1 (I use DFrobot Nano V3) is designed to control the motors with the 2x15 A driver.
It is connected to the connector Driver Interface (JST male connector 6 Holes). But there is a problem because the pin 4 of the connector, marked D6 is connected to pin 8 of Nano 1 instead of pin 6. This can not work because the pin 8 is not PWM !!!

Unless I am mistaken, this is apparently a problem with the design of GMR Board.

I sent two emails to DFRobot asking for explanations, but I have no response to date.

For people who use the GMR Board, have you encountered this problem? if so have you contacted and received information DFRobot?

Thank you in advance for your answers