Cripes (my Mum used to utter this when the old whirlpool twin tub spin cycle washing machine would dance across the laundry and separate itself from the water mains, flood the laundry and adjacent kitchen, but from not the AC mains)!
Got my XP-PEN display tablet - set it up - got it working sweet - as a third display on my Ryzen 7 desktop machine…
- Main display (Ubuntu says: #2
) on DisplayPort (NVidia) is 32" Lenovo - Secondary display (Ubuntu: #3 ) on DVI port (NVidia) is 23" Dell in portrait
- Tertiary display (Ubuntu: #1 : XP-Pen Display Tablet) on HDMI port (Nvidia)
The f–king tablet worked for days and days and across reboots, UNTIL I tried to use the 32" on my new Macbook, over HDMI, but the monitor wouldn’t sync to HDMI with something connected on DisplayPort - so - I went into “Displays” in Ubuntu and disabled output to the 32" on Displayport, powered the monitor off, set it (in the menu buttons on the monitor) to HDMI - hooked up the Macbook and it worked…
Currently (what works - in Ubuntu) :
- Main display (Ubuntu says: #2 ) on DisplayPort (NVidia) is 32" Lenovo
- Secondary display (Ubuntu: #1 ) on DVI port (NVidia) is 23" Dell in portrait mode
But now every time I plug the the tablet/display in (power it on, or pull out HDMI an re-insert [with some vigor I must add, in frustration], it comes on, displays manufacturer logo, briefly flashes my wallpaper then “no signal” (all this time the other monitors flick on and off several times - sometimes the portrait 23" in landscape). I’ve probably rebooted FIVE F–KING times!
Also - most times when I tried to power up the XP-Pen display - the 32" will power off, no signal, until I power cycle it a few times… Driving me batty!
My next step is to try several reboots with the DVI attached Dell 23" disabled, and disconnected and nothing hooked up to the DVI port on the NVidia GTX1650…
Maybe I’m due for a factory reset? Couldn’t hurt - all my $HOME data that I give a shit about is sync’d to my selfhosted cloud sync solution (ResilioSync - BTW it works flawlesslessly on Mac - better than it does on Linux) - and what isn’t is stored on my NAS.
A fresh install of Ubuntu 18.04 - get VPN working, NVidia drivers - do-release-upgrade to 20.04… but re-installing all those Steam games I hardly ever play? That’s the hardest part 
… I don’t play many of them very often - but - when I’ve got a hankering for one, it’s a huge enthusiasm crusher to know my 19th century tech broadband (it’s all copper based - thanks Politics and Rupert Murdoch) will probably take several hours to get me my fix…
– edit —
To avoid conflicts I’m now running the Macbook to my left, via Synergy, on a spare 27" FHD monitor…
