Thanks for sending the files. The problem is due to the fact that your encoding app is not updating the timecode in the Cineform metadata. When using Cineform, Resolve currently gives higher priority to the timecode in Cineform metadata. Moving forward, we will change it to just use Quicktime timecode.
I suppose you will have to provide about this black flickering at top then. If you have purchased the full version of the software, you can contact BMD support with the details, and send the clip and project which will show the problem.
>>From new RAW files to dnxhd 36 – speed: just 4-11 fps
>>From already used source RAW footage (used to render out to dnxhd yesterday) now when rendered again
Your bottleneck is your source drive. When the files are cached in RAM, the render is fast. Get a faster drive for your source!