FCC problem in EMC 55014

[HungLI]

Hi all, we are using ESP-12F from AI-thinker for our application and we are using ESP8266 to control whole appliance application included LCD display and we found 12F have not enough GPIO for our application so we used the SPi port to share the LCD control. The product development is fine in application till now but we have suffered the EMC test failure (EM55014) and 40MHz clock for the internal flash in 12F module is leakage to make EM55014 failure and we try to add a filter in external SPI line and it is improved a bit but not enough to make EMC test passed. Do you have any suggestion in hardware or software in order to get help on it. In addition, AI-thinker said that SPI port is not recommended for other application (only for internal flash usage only). is it right for the ESP8266 application?