I had the same problem with my DOIT ESP-WROOM-32 dev kit. I just could not get the MFRC522 board to be initialised. I connected the pins as per recommended even though you can configure the pins:

#define RFID_SDA 5
#define RFID_SCK 18
#define RFID_MOSI 23
#define RFID_MISO 19
#define RFID_RST 21 ...