Virtualization Station: Ubuntu 19.04 how to change display resolution?

[piscator]

We just got a TS-473 and I am playing around with virtual machines (in Virtualization Station).
I installed Ubuntu 19.04 and the max resolution it shows is 1024 x 768 (on my HD screen).
I cannot figure out how to change the resolution.

I already tried the following.

• https://www.qnap.com/en-us/how-to/faq/a ... t-monitor/
  Virtualization station does not have a Display option under Settings (Just Video, but nothing to change resolution)

• The default type under Settings / Video is "Cirrus". When I want to change resolution in Ubuntu it does not give an option to show higher than 1024 x 768.

• When I change the setting to 'QXL', I can change it in Ubuntu to "1920 by 1080" but then I only get 256 colors which look terrible.

• When I change the setting to 'VGA', I can change it in Ubuntu to "1280 by 720" (so the best I can find).

Any clues?