I am trying to add a 2nd monitor to a Nano - and BTW upgrade to 27inch monitors at the same time.
Device is using Jetpack 4.6 has been working fine for ages with HDMI output
I attached the 2nd monitor (which has itself been working fine with a Display Port connection for several years on another computer).
Upon booting the best response I initially got was the 2 screens displaying the logon prompt.
That in itself was strange as the Nano was set to ‘Auto Login’
It will not accept the password - just loops back to the login screen.
So I tried hot plugging it.
The second screen appears as a mirror of the first.
In Settings → Display it shows varying things. Sometimes 2 screens with ‘Mirror displays’ ticked; some times only one screen.
If you click ‘off’ mirrored displays and then ‘apply’ you pretty much lose control of the machine.
The icons in top right of screen vanish so you cant reboot/power off.
I tricked it once by having a terminal open and issued a manual reboot.
This results in 2 black screens although there are other indications that it has in fact rebooted.
Powering off-then-on from here still results in two black screens.
It is happy if either of the monitors are the only connection.
I cant remember fiddling with any other settings for this and my notes dont show anything.
I may have forced a resolution of 1920x1080 somewhere to keep a headless remote session happy but I am pretty sure this was in the Raspberry PI predecessor of the Nano.
Any suggestions ? Its all Black magic so even alchemy would be considered.