Hi Percy,
The issue is most likely the clocking on the I2S lines. You are in slave mode with an MCLK of 10 mHz resulting in a sample rate of exactly 39062.5 kHz. Unless your LRCK input is at EXACTLY 39062.5 kHz, you will have data errors.
The SPI lines should not effect the audio once the commands have been sent (unless of course you are changing register values...).
Best Regards,
dave