On my custom board I have a button BUTTON_1 in between supply voltage (Vbatt = 3V) and input on nRF52832 - therefore input will receive 3 Volts directly.
I have configured BUTTON_1 to:
{ BUTTON_1, false, NRF_GPIO_PIN_NOPULL, button_event_handler }
However when I push it the response comes with + 10 seconds delay, sometimes more.