Can't open serial port via minicom, but fine via Python and shell

I have been having issues with connecting to serial ports via minicom the last two weeks. For some reason, /dev/ttyACM0 maps to tty8 when I try to connect to it. My user is member of the dialout group, and the permissions on /dev/ttyACM0 seem to be set correctly. $ minicom -d /dev/ttyACM0 -b 115200 minicom: cannot open /dev/tty8: Permission denied $ ll /dev/ttyACM0 crw-rw-rw- 1 root dialoot 166, 0 Aug 16 12:02 /dev/ttyACM0 I also tried to setup a connection with pyserial, and this behaves as I expect.. >>> ser = serial.Serial('/dev/ttyACM0', 115200) >>> ser.write(b"Hello\n") 10 >>> ser.readline() b'Hello\r\n" >>> ser.readline() b'Hello: command not found\r\n' >>> ser.close() I tried installing the latest system updates (I run Zorin OS, based on Ubuntu 20.04 LTS) and rebooting several times. I also tried different USB ports, without results. Does anyone have an idea what could be wrong with my setup here? Edit: I just got the idea to communicate directly via my shell, and this seems to be working. I therefore think it is a minicom issue. Still very strange, since I can't find other people with the same problem. $ cat /dev/ttyACM0 $ echo "Hello\n" > /dev/ttyACM0 $ cat /dev/ttyACM0 Hello Hello: command not found