NetworkSerialPort timeout on rfc2217_send_purge

[f-scholer]

I have a setup where the exporter and coordinator runs on a remote server with access to my device. I am trying to access the serial port of my device from my local machine. This initially seems to work fine and I can access the serial port just fine for using the labgrid-client "console" command.

However, when I try to use the serialport from a pytest the serial port no longer works, and I get:

serial.serialutil.SerialException: Could not open serial port rfc2217://server:44055?ign_set_control&timeout=3.0: timeout while waiting for option 'purge'

Works (I get an interactive console):
labgrid-client -x s70 -c hil.yaml console

Fails:
pytest --lg-coordinator s70 --lg-env hil.yaml test.py

hil.yaml:
targets:
main:
resources:
RemotePlace:
name: 'hil-s70'
drivers:
SerialDriver: {}

test.py:
import pytest
def test_command(target):
serial = target.get_driver("SerialDriver")

Output log is attached:
labgrid.log

I did a manual reinstall of the labgrid-serial fork (pyserial-labgrid==3.5.0.2)