L6229Q bldc motor control

[pcbsmt]

[This inquiry was made using a translator. Please understand.]

hello.
I would like to inquire about how to control a BLDC motor using the L6229Q motor driver.

The operating environment is as follows.
MCU: STM32G431KBUx
MotorDriver: L62229Q

The motor was controlled using the PWM of the MCU.

The PWM signal is connected to the Vref pin of L6229Q.

PWM frequency: 16.6kHz

The motor works well, but there are two problems.

1. There is a change in motor speed from duty ratio 0% to 27%.
   However, there is no change in speed at a duty ratio of 27% or higher.
   It seems strange that the motor's limit is reached even with a small duty ratio.
2. A high-frequency sound is heard when the motor's current consumption is approximately 240 mA or more.
   Even if you increase the PWM frequency, the sound is the same.

The schematic of L6229Q is attached.

If you know the cause, please help.

[pcbsmt]

In case of problem number 2, it does not seem to be a circuit problem as the sound comes from the motor rather than the PCB.