Created attachment 159039 [details] the four files SUMMARY I create a rectangle to blur a video piece, which works as expected in the preview but applies differently when rendering to a file. STEPS TO REPRODUCE 1. Duplicate the video track 2. At the upper track, adds "Alpha shapes (mask)" 3. Create any rectangle you want 4. At the upper track, adds "Gaussian blur" 5. set sigma to 20 OBSERVED RESULT The preview blurs the rectangle, but the rendered file doesn't. EXPECTED RESULT Both should apply the effect in the same way. SOFTWARE/OS VERSIONS macOS: 12.6.5 ADDITIONAL INFORMATION In the attachment, I'm adding a zip file containing the following: - A record of kdenlive preview where you can see the effect working as intended - The rendered file where you can see the effect is present, but in a much different way - The original video without effect and the .kdenlive project file in case you want to reproduce it.