Pins are denied to work as GPIO after the TWIM "Initialization -> Deinitialization" cycle.
After deinitialization, respectively, disable pins from the periphery, using the function nrf_pin_cfg_default()
But their further use as GPIO pins remains impossible (the log levels do not change)
Before the first TWIM initialization, the pins function normally.
TWI instance and pins used:
TWIM1
NRF_GPIO_PIN_MAP(0, 7) // I2C SDA
NRF_GPIO_PIN_MAP(0, 6) // I2C SCL
In continuation of this topic - https://devzone.nordicsemi.com/support/220139