ESP32: Guru Meditation Error: Core 1 panic'ed (StoreProhibited)

I've been working on a LED strip lately trying to create all kinds of animations. But one of them has caused quite a lot of trouble. It's meant to be a kind of firework.

It usually runs once and when the loop starts a second time the following error comes up exactly the same time.

Guru Meditation Error: Core  1 panic'ed (StoreProhibited). Exception was unhandled.
Core 1 register dump:
PC      : 0x400eae48  PS      : 0x00060330  A0      : 0x800d133a  A1      : 0x3ffb1f30  
A2      : 0x0000000e  A3      : 0xbffc0553  A4      : 0x9999999a  A5      : 0xbfb99999  
A6      : 0x7ff00000  A7      : 0x80671eb4  A8      : 0x0000000d  A9      : 0x0000000e  
A10     : 0x00000001  A11     : 0x00000000  A12     : 0x0000000d  A13     : 0x0000000d  
A14     : 0x00000039  A15     : 0x00000000  SAR     : 0x00000020  EXCCAUSE: 0x0000001d  
EXCVADDR: 0xbffc0553  LBEG    : 0x400014fd  LEND    : 0x4000150d  LCOUNT  : 0xffffffff  

Backtrace: 0x400eae48:0x3ffb1f30 0x400d1337:0x3ffb1f50 0x400d137d:0x3ffb1f90 0x400d23b1:0x3ffb1fb0 0x40088535:0x3ffb1fd0

using the ESP Exception Decode gave the following result:

PC: 0x400eae48: hsv2rgb_rainbow(CHSV const&, CRGB&) at C:\Users\Tom\Documents\Arduino\libraries\FastLED-3.4.0\src\hsv2rgb.cpp line 492
EXCVADDR: 0xbffc0553

Decoding stack results
0x400eae48: hsv2rgb_rainbow(CHSV const&, CRGB&) at C:\Users\Tom\Documents\Arduino\libraries\FastLED-3.4.0\src\hsv2rgb.cpp line 492
0x400d1337: feuerwerk() at C:\Users\Tom\Documents\Arduino\libraries\FastLED-3.4.0\src/pixeltypes.h line 181
0x400d137d: loop() at C:\Users\Tom\Desktop\fastledtest/fastledtest.ino line 109
0x400d23b1: loopTask(void*) at C:\Users\Tom\Documents\ArduinoData\packages\esp32\hardware\esp32\1.0.4\cores\esp32\main.cpp line 19
0x40088535: vPortTaskWrapper at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/freertos/port.c line 143

This is my function where the error has to be:

void feuerwerk() {
  float gravity = 0.004;
  float pos = 0;
  float minmax = 0.3;
  
  float vel = random16(sqrt((NUM_LEDS * minmax) * (2 * gravity)) * 1000, sqrt((NUM_LEDS * (1 - minmax)) * (2 * gravity)) * 1000);
  vel = vel / 1000;
  float startvel = vel;
  
  uint8_t brightness = 200;
  if(random8(2) == 1) { 
    while (vel >= -0.075) {
      pos += vel;
      pos = constrain(pos, 0, NUM_LEDS - 1);
      vel -= gravity;
      leds[int(pos)].setHSV(0, 0, brightness);
  
      if (vel >= 1) {
        leds[int(pos) - 1].setHSV(0, 0, brightness);
      }
  
      if(int(pos) % 3 == 0) brightness--;
      
      fadeToBlackBy(leds, NUM_LEDS, 18);
      FastLED.show();
    }
  }
  else {
    while (vel >= -0.2) {
      pos += vel;
      pos = constrain(pos, 0, NUM_LEDS - 1);
      vel -= gravity;
      leds[NUM_LEDS - int(pos)].setHSV(0, 0, brightness);
  
      if (vel >= 1) {
        leds[NUM_LEDS - int(pos) + 1].setHSV(0, 0, brightness);
      }
  
      if(int(pos) % 3 == 0) brightness--;
      
      fadeToBlackBy(leds, NUM_LEDS, 18);
      FastLED.show();
    }
    pos = NUM_LEDS - int(pos);
  }
  //<Sparkinitialisierung

  byte faktor = 8;
  for(int i = 0; i < NUM_SPARKS; i++) {
    sparkpos[i] = pos;
    //sparkvel[i] = random16(0.3 * startvel * 1000, 2 * startvel * 1000);
    sparkvel[i] = random16(0, faktor * startvel * 1000);
    sparkvel[i] = sparkvel[i] / 1000;
    sparkvel[i] = sparkvel[i] - startvel * (faktor / 2);
    sparklum[i] = random8(100, 255);
    //Serial.println(sparkvel[i]);
  }
  
  //</Sparkinitialisierung
  sparklum[0] = 255;

  byte cooldown = 1;
  
  while(sparklum[0] > 0) {
    Serial.println(sparklum[0]);
    for(int i = 0; i < NUM_SPARKS; i++) {
      if (sparklum[i]) {
        if (sparkpos[i] < NUM_LEDS && sparkpos[i] >= 0) {
          sparkpos[i] += sparkvel[i];
        }
        if (sparkvel[i] > 0.1 ) {
          sparkvel[i] -= faktor * gravity;
        }
        if (sparkvel[i] < -0.1) {
          sparkvel[i] += faktor * gravity;
        }
        if (sparklum[i] < cooldown) {
          sparklum[i] = 0;
        }
        else{
          sparklum[i] -= cooldown;
        }
        leds[int(sparkpos[i])].setHSV(0, 0, sparklum[i]);
        
      }
    }
    fadeToBlackBy(leds, NUM_LEDS, 25);
    FastLED.show();
  }
}