COSplay CLI will not detect device on new machine

I am trying to run the CLI COSplay on my new laptop (testing purposes ahead of our submission, since reviewers may not have ParaVision). I have recently pushed a commit which makes it possible to run the CLI interface on a machine without PV. That part seems to work well. As does the connection as mass storage device. However the CLI will simply not detecht the device:

chymera@zenhost ~ $ lsusb
Bus 004 Device 004: ID 05e3:0749 Genesys Logic, Inc. 
Bus 004 Device 005: ID 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter
Bus 004 Device 003: ID 2109:0813 VIA Labs, Inc. 
Bus 004 Device 002: ID 2109:0813 VIA Labs, Inc. 
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 007: ID 04f3:0903 Elan Microelectronics Corp. 
Bus 001 Device 005: ID 8087:0a2b Intel Corp. 
Bus 001 Device 003: ID 13d3:5755 IMC Networks 
Bus 001 Device 006: ID 2109:d101 VIA Labs, Inc. 
Bus 001 Device 046: ID f055:9802  
Bus 001 Device 004: ID 2109:2813 VIA Labs, Inc. 
Bus 001 Device 002: ID 2109:2813 VIA Labs, Inc. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
chymera@zenhost ~ $ ls -lah /etc/udev/rules.d/95-pyboard.rules 
-rw-r--r-- 1 root root 472 Sep  5 20:48 /etc/udev/rules.d/95-pyboard.rules
chymera@zenhost ~ $ cat /etc/udev/rules.d/95-pyboard.rules 
# f055:9800, 9801, 9802 MicroPython pyboard
ATTRS{idVendor}=="f055", ENV{ID_MM_DEVICE_IGNORE}="1"
ATTRS{idVendor}=="f055", ENV{MTP_NO_PROBE}="1"
SUBSYSTEMS=="usb", ATTRS{idVendor}=="f055", MODE="0666"
KERNELS=="ttyACM*", ATTRS{idVendor}=="f055", MODE="0666"
SYSFS{idVendor}=="f055", ENV{ID_MM_DEVICE_IGNORE}="1"
SYSFS{idVendor}=="f055", ENV{MTP_NO_PROBE}="1"
SUBSYSTEMS=="usb", SYSFS{idVendor}=="f055", MODE="0666"
KERNELS=="ttyACM*", SYSFS{idVendor}=="f055", MODE="0666"
chymera@zenhost ~ $ eix pyserial
[I] dev-python/pyserial
     Available versions:  3.2.1 (~)3.4 {doc examples PYTHON_TARGETS="pypy python2_7 python3_4 python3_5 python3_6 python3_7"}
     Installed versions:  3.4(20:30:27 05/09/18)(-doc -examples PYTHON_TARGETS="python2_7 python3_6 -pypy -python3_4 -python3_5 -python3_7")
     Homepage:            https://github.com/pyserial/pyserial https://pypi.org/project/pyserial/
     Description:         Python Serial Port extension

chymera@zenhost ~ $ echo $PYTHONPATH
/home/chymera/.python_develop:/home/chymera/.local/lib64/:
chymera@zenhost ~ $ echo $PATH
/home/chymera/utils:/home/chymera/.python_develop:/home/chymera/.local/bin:/usr/lib/llvm/6/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/bin
chymera@zenhost ~ $ which COSplay
/home/chymera/.local/bin/COSplay
chymera@zenhost ~/src/sci/sci-libs/spams-python $ COSplay --vendor none

Press Ctrl+c when you are done to close the program.

Searching port...

It hangs at the last step forever.

I have no idea what it could be. I am thinking maybe something unobvous is making my PV-free solution not work, or maybe the USB-C adaptor is subtly somehow messing things up? Though lsusb seems to list the device just fine.

@faymanns any ideas?

IBT-FMI / COSplay

COSplay CLI will not detect device on new machine #31