USBX CDC ACM There is a problem with ux_device_class_cdc_acm_write

[arilink-tech]

I ported ThreadX and USBX on STM32F105RBT6. The USBX HID works well. When I try to use USBX CDC, the problem arises. I am using The USBX sample app of x-cube-azrtos-f4. When I use the USB virtual serial port to send data to the serial port 3, everything is normal. When I use the serial port 3 to receive data and send it to the USB virtual serial port, the problem occurs. When the data exceeds a certain amount, HAL_UART_RxCpltCallback () It can still trigger and receive data from the serial port, but ux_device_class_cdc_acm_write does not work properly. Why?