Arduino MKR Zero external Micro SD card

I have been trying to get an external MircoSD card module to work with my Arduino MKR ZERO. I tried changing the SD library SPI pins based on this.

I changed the variant.h from this:

// Needed for SD library
#define SDCARD_SPI      SPI1
#define SDCARD_MISO_PIN PIN_SPI1_MISO
#define SDCARD_MOSI_PIN PIN_SPI1_MOSI
#define SDCARD_SCK_PIN  PIN_SPI1_SCK
#define SDCARD_SS_PIN   PIN_SPI1_SS

To this:

// Needed for SD library
#define SDCARD_SPI      SPI
#define SDCARD_MISO_PIN PIN_SPI_MISO
#define SDCARD_MOSI_PIN PIN_SPI_MOSI
#define SDCARD_SCK_PIN  PIN_SPI_SCK
#define SDCARD_SS_PIN   PIN_SPI_SS

and it didn't work no matter what I tried. I always get initialization failed.

only comment out the SDCARD_ defines from variant.h

Commenting them out doesn't help, I still get the initialization failed.

then the problem is somewhere else

Do you have any idea what could it be then ? I haven't changed anything anywhere else beside this and startup file where I defined CRYSTALLESS. I'm using it without the external 32.768 Khz crystal and It runs any other program just fine.

it is a custom board? try it first with normal MKR Zero. there are enough problems with SD card wiring to an established board