SPI HCT595 LEDs controlling

[fabi1415]

I try to controll the HCT595D with an ESP32 over SPI. I use C++ and Visual basic studios
CODE:

#include <SPI.h>
#include <Arduino.h>
  
#define SCK  6   
#define MOSI 8  
#define SS   6    

void initSPI() {
  SPI.begin(SCK, -1, MOSI, SS); 
  pinMode(SS, OUTPUT);
  digitalWrite(SS, HIGH);
}

void sendSPI(uint8_t data) {
  digitalWrite(SS, LOW);
  SPI.transfer(data);
  digitalWrite(SS, HIGH);
}

void setup() {
  Serial.begin(115200);
  initSPI();
}

void loop() {
  
  Serial.println("Sende 0x00");
  sendSPI(0xAA);
  delay(1000);
 
  Serial.println("Sende 0x55");
  sendSPI(0x55);
  delay(1000);
}
```But i always get thsi weird output:

rst:0x8 (TG1WDT_SYS_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0030,len:1184
load:0x40078000,len:13232
load:0x40080400,len:3028
entry 0x400805e4
ets Jul 29 2019 12:21:46

Does anyone know if that is an Hardware Problem, because  i don´t see the mistake in the code

[kmin]

@fabi1415

#define SCK  6   
#define MOSI 8  
#define SS   6  

SCK and SS on the same pin number??

Also, if you have normal Esp Wroom32 devboard, don't use Gpio6...11, they are connected to boards SPI flash memory.
Default Esp32 SPI pins:
MOSI GPIO 23
MISO GPIO 19
CLK (SCK) GPIO 18
CS (SS) GPIO 5

Or use any pins from Gpio16 to 33