At least v4.1 does not take into account that ESP32 chips can have an usable GPIO20 yet. We'll see if we can add/backport this. For now, you may be able to make this change to make it work: in esp-idf/components/soc/soc/esp32/gpio_periph.c, search for 'IO_MUX_GPIO19_REG' and change the line under i...