No ports are detected even though the Arduino UNO is connected to the front port (some time ago it wasn't detected when connected to the back, but it was when connected to the front, now its reversed).
Connected to the front (doesn't work):
lsusb:
❯ lsusb
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 002: ID 1058:2621 Western Digital Technologies, Inc. Elements 2621
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 002: ID 046d:c092 Logitech, Inc. G203 LIGHTSYNC Gaming Mouse
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 002: ID 090c:6300 Silicon Motion, Inc. - Taiwan (formerly Feiya Technology Corp.) USB2.0 Card Reader
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Connected to the back (works):
❯ lsusb
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 002: ID 1058:2621 Western Digital Technologies, Inc. Elements 2621
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 002: ID 046d:c092 Logitech, Inc. G203 LIGHTSYNC Gaming Mouse
Bus 003 Device 003: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial adapter
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 002: ID 090c:6300 Silicon Motion, Inc. - Taiwan (formerly Feiya Technology Corp.) USB2.0 Card Reader
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Ubuntu 20.04.
Arduino IDE 2: 2.0.2, 2.0.3, 2.0.4-nightly-20230219
I think that you're better of asking this in a Linux forum. If your operating system does not recognise the board, the IDE will never recognise it.
That's more than likely your board. What does dmesg say when you connect it? Disconnect the board, run dmesg -w. When the output finishes, connect the board and check what happens.
dmesg -w result after connecting to back USB port:
[35410.493646] usb 5-1: new full-speed USB device number 10 using xhci_hcd
[35410.656565] usb 5-1: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.54
[35410.656575] usb 5-1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[35410.656580] usb 5-1: Product: USB2.0-Serial
[35410.661648] ch341 5-1:1.0: ch341-uart converter detected
[35410.675688] usb 5-1: ch341-uart converter now attached to ttyUSB0
And after connecting to the front USB port:
[35493.919569] usb 1-7: new full-speed USB device number 24 using xhci_hcd
[35494.174007] usb 1-7: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.54
[35494.174017] usb 1-7: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[35494.174021] usb 1-7: Product: USB2.0-Serial
[35494.181817] ch341 1-7:1.0: ch341-uart converter detected
[35494.195850] usb 1-7: ch341-uart converter now attached to ttyUSB0
dmesg tells you the devices connected to the computer.
The IDE is telling you that, at its priv level (probably not in dialout group), it sees no comm ports.
Thanks for the clarification. That backs this prognosis:
Rather than the alternative:
It is still a problem regardless, but it's important to determine which layer the problem is occurring at so you can focus your attention in the right place.
It's not the dialout group or a priv level. USB detection is far before the dialout group comes into the picture. The dialout group only comes into the picture during communication with the USB device; in the Arduino world that would be opening serial monitor or uploading a sketch.
What also was against the dialout group is that adding yourself (or someone) to the dialout group applies to all ports, not a specific one. And OP could communicate with the board on one of the USB ports; so that excludes possibility that the dialout group is the culprit.