a "aconnect -l" command gives me this:
client 0: 'System' [type=kernel]
0 'Timer '
1 'Announce '
client 14: 'Midi Through' [type=kernel]
0 'Midi Through Port-0'
the lsusb command gives this:
Bus 001 Device 009: ID 1fc9:8260 NXP Semiconductors
Bus 001 Device 003: ID 045e:0752 Microsoft Corp. Wired Keyboard 400
Bus 001 Device 002: ID 1a40:0101 Terminus Technology Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
so the first device is being recognized but not the second USB Midi Device, but it is not shown on the "aconnect -l" command
If you disconnect and re-connect your usb devices and then "dmesg | tail -20", does your machine recognise that something has been connected?
Nothing changes only when I disconnect one USB Midi device and then "dmesg | tail -20" I got this:
[ 1226.933052] usb 1-1.3: USB disconnect, device number 11
and the same with the other one I got this:
[ 1368.249413] usb 1-1.2: USB disconnect, device number 8