V5 Motor decreases output over time.

NOTE: This involves beta components.

When we are using the beta equipment for a drivetrain, the max torque gradually drops after 2 minutes of driving, and after 30 seconds, the robot is essentially inoperable. I have checked the data for the motors and it seems they are maxing out at around 0.3 Nm of torque, and are utterly incapable of moving the robot, even though the system shows a desired velocity of 200 RPM. After this time we have to let the robot rest for a while before it can perform again. Of our 4 motors, one has already died, two behave like this, and the fourth is flawless.