For the sake of completeness, I found my error.
I assumed, due to the writing on the back, that the ports must be 21/22. However, the SDA/SCL ports for the groove port are 32/33.
while (!scales.begin(&Wire, 32, 33, DEVICE_DEFAULT_ADDR))
{
Serial.println("scales connect error");
M5.Lcd.print("scales connect error");
delay(1000);
}
Changing the ports in the scales.begin fixed the error.
Greetings Pascal
