I can't get my thumby's to connect to the web editor on Linux (Debian 11 and Fedora 36) the same thumby, cable and PC work in windows.

lsusb shows a MicroPython device in it and it also works in BOOTSEL (holding the down button while turning it on)

listing /dev/tty* doesn't show a ttyUSB device

Try adding your user to the dialout group:

Code Select Expand

sudo adduser $USER dialout

You may need to log out and back in or reboot afterwards