Live preview - nothing visible

[MWP]

I'm using the latest debian/ubuntu package, version 1.95 on LinuxMint 22 x86_64.

Nothing is displayed in the live preview window at all. It's just an empty box.

When run from the console, this is the output:

/usr/lib/python3/dist-packages/pdfkit/source.py:11: SyntaxWarning: "is" with 'str' literal. Did you mean "=="?
  if self.type is 'file':
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
AcceleratedSurfaceDMABuf was unable to construct a complete framebuffer
(... continues)