Final render uses timeline preview render as input
If there are any pre-rendered preview zones on timeline, Kdenlive seems to also use these for final render, although it should actually use original high-quality clips instead. As a result, the rendered video looks blurry in the places that had pre-rendered preview zones on timeline.
Tested with Kdenlive 19.12 beta (kdenlive-19.12.0-beta1-x86_64.appimage
) and latest daily build (kdenlive-20.03.70-63c88b1-x86_64.appimage
)