Mismatch at vendor motor values and sample screen motor values.

[retrodorian]

Hi, I am using 131:1 Metal Gearmotor 37Dx73L mm 24V with 64 CPR Encoder (Helical Pinion) with BTS7960 motor driver. I am sure about my connections between motor, driver and teensy4.1. According to the vendor, the motor parameters should be these:

This gearmotor is a powerful 24V brushed DC motor with a 131.25:1 metal gearbox and an integrated quadrature encoder that provides a resolution of 64 counts per revolution of the motor shaft, which corresponds to 8400 counts per revolution of the gearbox’s output shaft. 24V no load rpm is 79 RPM.

When I use these information at config file with this setup:

#define MOTOR_MAX_RPM 79
#define MAX_RPM_RATIO 0.85
#define MOTOR_OPERATING_VOLTAGE 24
#define MOTOR_POWER_MAX_VOLTAGE 22
#define MOTOR_POWER_MEASURED_VOLTAGE 24
#define COUNTS_PER_REV1 8400
#define COUNTS_PER_REV2 8400
#define COUNTS_PER_REV3 8400
#define COUNTS_PER_REV4 8400
#define WHEEL_DIAMETER 0.125
#define LR_WHEELS_DISTANCE 0.356
#define PWM_BITS 10
#define PWM_FREQUENCY 20000

The sample screen output is this:
Encoder readings:
M1 : 231916
M2 : 224359
M3 : 227752
M4 : 224081

Counts Per Revolution
M1 : 17493
M2 : 16937
M3 : 17178
M4 : 17018

There is a mismatch at CPR I believe. What should I do, also why there is an inconsistency between vendor and firmware? Thank you beforehand.