Firmware upgrade expansion board v 3.2 manjaro

[Ph0333nix]

hi, do we have any linux users who managed to do the firmware upgrade on the expansion-board (which is step one of https://docs.pycom.io/gettingstarted/connection/lopy4/) ?
when I follow the steps specified (https://docs.pycom.io/pytrackpysense/installation/firmware/) I get the error messages: "dfu-util: Cannot open DFU device 04d8:ef99"
and "dfu-util: No DFU capable USB device available". I searched for solutions all day and am none the wiser so I thought maybe someone here encountered this issue and managed to solve it, if so any tips are much appreciated!
what I did:
I installed dfu-util
I added myself to the uucp group (instead of dialout, because as I understand it that does not exist for manjaro but uucp seems to be the one i need to use instead. I came to this conclusion after I did a "stat /dev/ttyACM0").

1. Disconnect the USB cable
2. Hold down the S1 button on the shield
3. Connect the USB cable
4. Keep the S1 button pressed for at least one second
5. Release the button. When the board is connected in DFU-mode, it will be in this state for 7 seconds.

this is the output:

DFU suffix version 100
Match vendor ID from file: 04d8
Match product ID from file: ef99
dfu-util: Cannot open DFU device 04d8:ef99
dfu-util: No DFU capable USB device available

[Ph0333nix]

Never mind, I found the solution. For anyone who faces this same problem: you have to add yourself to the "storage" group to solve this problem :)