The RFID module might be interfering with the WiFi signal. Try using a different power source or check if the RFID is drawing too much current and test with a different router or 2.4GHz channel.

Adding multiple modules to an M5Stick is possible, but you'll need to plan the connections carefully to avoid pin conflicts. Check the pinouts and consider using an expansion board. With the right firmware, you can get both the CC1101 and PN532 working together.

Try running M5Burner from the terminal to check for any error messages and make sure you have the latest version, and that Python & dependencies are installed correctly.