Checkbox not visible when install Dutch (Nederlands) on 800*600 Oracle virtual Box

Hi,

If you try to install Ubuntu on an Oracle VirtualBox machine in Dutch (Nederlands), the checkboxes (quit) (back) (continue) cannot be seen (=out of visible screen) witch is 800*600.

The check boxes are on a usable/seen place in French and English, same default screen 800*600. I didn't check other languages so far.

I noticed the same problem with guest in Ubuntu versions 18.04.5 LTS, 20.04 and in groovy-desktop-amd64 as of Oct 8, 2020. So, it is not a regression.

N.B.: in VirtualBox, the OS installation screen is 800*600. I suspect that the problem will be the same with an install on a bare machine where the screen is 800*600 only but I have no way to test it now.

Host : Ubuntu 18.04 with daily updates as of Oct 8, 2020
8 Gb Ram
Oracle VirtualBox Version 6.1.12 r139181 (Qt5.9.5)
The VM is "vanilla" but for the RAM I upgrade from 1 to 3 or 4 Gb Ram and the size of the virtual disk upgraded from 10 to 20 Gb.