I am having a similar issue with Octa4a installed on my Pixel 3 and trying to connect to my MakerBot Replicator 2X. It says printer is connected and I tried the different driver options but when I try to connect through the portal interface I get the "No working port/baudrate combination detected" error. Here is the log
Changing monitoring state from "Offline" to "Detecting serial connection"
Performing autodetection with 7 port/baudrate candidates: /dev/ttyOcto4a@115200, /dev/ttyOcto4a@250000, /dev/ttyOcto4a@230400, /dev/ttyOcto4a@57600, /dev/ttyOcto4a@38400, /dev/ttyOcto4a@19200, /dev/ttyOcto4a@9600
Trying port /dev/ttyOcto4a, baudrate 115200
Unexpected error while connecting to serial port /dev/ttyOcto4a, baudrate 115200 from hook GPX: Timeout: 'Timeout' @ comm.py:_open_serial:3832
Could not open port /dev/ttyOcto4a, baudrate 115200, skipping
Trying port /dev/ttyOcto4a, baudrate 250000
Unexpected error while connecting to serial port /dev/ttyOcto4a, baudrate 250000 from hook GPX: Timeout: 'Timeout' @ comm.py:_open_serial:3832
Could not open port /dev/ttyOcto4a, baudrate 250000, skipping
Trying port /dev/ttyOcto4a, baudrate 230400
Unexpected error while connecting to serial port /dev/ttyOcto4a, baudrate 230400 from hook GPX: Timeout: 'Timeout' @ comm.py:_open_serial:3832
Could not open port /dev/ttyOcto4a, baudrate 230400, skipping
Trying port /dev/ttyOcto4a, baudrate 57600
Unexpected error while connecting to serial port /dev/ttyOcto4a, baudrate 57600 from hook GPX: Timeout: 'Timeout' @ comm.py:_open_serial:3832
Could not open port /dev/ttyOcto4a, baudrate 57600, skipping
Trying port /dev/ttyOcto4a, baudrate 38400
Unexpected error while connecting to serial port /dev/ttyOcto4a, baudrate 38400 from hook GPX: Timeout: 'Timeout' @ comm.py:_open_serial:3832
Could not open port /dev/ttyOcto4a, baudrate 38400, skipping
Trying port /dev/ttyOcto4a, baudrate 19200
Unexpected error while connecting to serial port /dev/ttyOcto4a, baudrate 19200 from hook GPX: Timeout: 'Timeout' @ comm.py:_open_serial:3832
Could not open port /dev/ttyOcto4a, baudrate 19200, skipping
Trying port /dev/ttyOcto4a, baudrate 9600
Unexpected error while connecting to serial port /dev/ttyOcto4a, baudrate 9600 from hook GPX: Timeout: 'Timeout' @ comm.py:_open_serial:3832
Could not open port /dev/ttyOcto4a, baudrate 9600, skipping
Changing monitoring state from "Detecting serial connection" to "Error"
Changing monitoring state from "Error" to "Offline after error"