White diagonal lines on the note preview panel in version 0.11.8

Current behavior

White lines appear on the background in the preview panel when using Dark, Monokai, or Solarized Dark interface theme.

The lines occasionally disappear after clicking and opening an other note.

Steps to reproduce

1. Switch to Dark, Monokai, or Solarized Dark interface theme.
2. Create or edit a note
3. Exit the editing view by clicking outside of the editor panel
4. Sometimes you have to enter then exit edit mode a second time for these lines to appear.

Environment

• Version : 0.11.8
• OS Version and name : Windows 10