OS: Ubuntu 20.04

Device: RPi Pico

main.py:

from machine import Pin
from time import sleep
led = Pin(25, Pin.OUT)
n = 0

while True:
    led.toggle()
    print("13 x {} = {}".format(n, 13*n)) # print the thirteen-times table
    n = n+1
    sleep(0.5)

With MicroPython 1.17, when I plug this device in, connect with tio and press Ctrl+C, then it successfully interrupts and gives me normal prompt. When I, instead, first press Ctrl+A and then Ctrl+C, then nothing happens and the input kind of gets stuck (if I do it via pyserial, then the write method blocks). Same happens when I press Ctrl+D and then Ctrl+C.

Sometimes I get out of this situation by hard-resetting Pico, but sometimes even this doesn't help and I need to either restart my computer or reset USB.

When I go back to 1.16, then this problem disappears.

This issue is relevant for Thonny IDE, because upon connecting a device, it sends Ctrl+A to probe whether the device is already idle at prompt or a process is running.