Does Linux have software protection on USB? Or has the magic smoke escaped?
The fact that you're referencing ttyUSB0 tells me you have cheap Chinese clones and not genuine Ardunios.  These are usually based around the CH340 USB interface chip which is notoriously unreliable.
Your UNO is dead.
My supposition is that plugging it in cripples the CH340 driver.  Any other boards that you subsequently plug in can not be recognised because the driver is in a bad state.
To prove this:

Unplug the UNO
Reboot (power cycle) the computer
Plug in the Nano

It should recognise the Nano fine.

Unplug the Nano
Plug in the UNO

It should fail now.

Unplug the UNO
Plug in the Nano

The Nano should now also fail.
If that sequence is correct then the Uno is definitely dead. Throw it away, or at least never plug it in through USB ever again (you could program over serial through the TX/RX pins or using ICSP as if it were a breadboard Arduino though).