SAMD21 Pro RF bootleader / device

Hi,

Having issues with the Pro RF - Arduino IDE can’t load Blink or other sketches to the board. I assume this has to do with it’s USB device status, having already loaded sketches on a Mac with success. My environment:

-Ubuntu 21.10 Host, Ubuntu 21.10 Guest inside Virtual Box.

-I am passing USB devices to other boards in this environment (SF ESP32 gateways and Adafruit Feathers).

-I have followed the Lora tutorial and installed the board manager and I have tried resetting the boot loader - I get the slow pulse on the blue STAT LED.

-It registers the device as a/dev/ttyACM0, rather than the ```
/dev/cu.usbmodem####


-My error message on uploading is ```
avrdude: stk5000v2_ReceiveMessage(): timeout

On checking again, I can recognize and load it correctly on OSX. Any help appreciated - I am desperate to move this code off my this machine (where it doesn’t belong for like 5 reasons) an onto my work machine. Thanks!