I've been following this in the Debian bug reports and at Oracle Vbox bug reports, since appx. July 3rd when it first appeared for me. Sent them logs and some feedback.
A week ago I tried to install the version directly from
www.virtualbox.org. Even though I thought I had completely uninstalled vbox from my system, I kept getting messages about dependencies that could not be met when I tried to install their deb files.
I have a pretty good system backup regimen so I just restored my backup with version: VirtualBox 5.2.14-dfsg-2
That version works fine for me in Siduction. (Version 5.2.10 also works fine in Linux Mint)
The Debian /unstable maintainers will probably get a handle on this soon anyway.
Thanks for your reply.