Unless I missed something, poster still has not stated which Sparky, especially rolling or stable.
As always, posting the output of inxi -br wouid be quite sufficient.
For myself in Debian stable etc/apt/source...
deb http://download.virtualbox.org/virtualbox/debian
bionic contrib
the bionic contrib was truncated off of the end via the forum software/
For rolling or unstable, I would go with the posters above.
Virtualbox tracks Ubuntu more, but I have not had problems in Virtualbox since Stretch was in early testing (2016). "bionic" would be the version name for stable and lts.
Side issue. qemu/kvm had hiccups with Windows 7 in 2015 so I went with virtualbox. My license for 7 keeps me in virtualbox for ease. If I ever go to 10 for moms finances, I would go with qemu/kvm. It has matured enough. Virtual box spends more effort in supporting Ubuntu and RedHat variants. Debian does take the high and soemtimes very high road on FOSS. There can be hiccups, especially in testing.