@totalsonic Thanks for that lucid explanation. I'll just wait patiently for 20.04.
Regards,
Linky

Apps running in xenial in landscape work as ecpected when displayed through an external monitor but not on the phone's screen.
The graphics (in this case aisleriot) displays fully. The touchscreen works in the left two-thirds only.
Is there a fix?

I'm running aisleriot in the xenial libertine container. It is flawless in portrait orientation. In lanscape, the graphics expand to the full area of the display but the x-axis of the screen digitiser doesn't work on the right side.
This is on a clean install of UT 16.04 2021/2/13. UT apps all function fully in portrait.
I have found no suggestions for a solution so far.
Advice would be appreciated. I'm a UT beginner, by the way.