Scrivener on Linux is a mix of pros and cons. It obviously runs better in its native environment, and a few things don’t work well that some might consider essential, but on the other hand everything around Scrivener isn’t Windows… so there’s that. 
Still… You can see the drunk typesetting problem persists even with Calibri (between the ‘k’ and ‘e’ in ‘backed’). It would be good to know the bug was flagged for a developer.
There’s not much they can do about it regrettably. You could try adjusting the PDF output settings in the Editor: Options tab, File ▸ Options.... As I understand it, they have provided us with all of the tools they have available themselves, for tinkering with the quality of the text output for PDF in those settings.