This is the snippet of the console output in OctoPrint that was coming up for me.
Send: N23 G1 X89.30 Y18.84 E1.00305*83
Unexpected error while reading serial port: SerialException: 'device reports readiness to read but returned no data (device disconnected or multiple access on port?)' @ comm.py:_readline:832
Changing monitoring state from 'Printing' to 'Error: SerialException: 'de...'
The problem turned out to be with the power that my Portabee was receiving from the power brick. I've recently did some rewiring by adding some click-in connectors so it's really easy to disconnect the printer and remove it from inside its box. One of these connectors, notably, the power connector wasn't making good contact. There was a piggy backed connected coming off of this that was feeding just enough power to the printer to do some operations manually, but when the the device was in print mode and using constant power, the Gen6 board would simply reset as it wasn't getting enough juice.
I fixed this by using a heavier gauge wire to connect the click-in connectors, now there are no more resets and its printing just fine!