For some reason if you are working on a vertical timeline (1080x1920) and add a photo, add Blanking Fill, then add the Dynamic Zoom, it causes a ton of grain to the blank fill image and adds a stuttery zoom to the blank fill image as well.
On a horizontal timeline, this doesn't happen. The blank fill image doesn't have any zoom or grain added. But once I switch it to Portrait, then this problem occurs.
I have had it happen on 3 different projects now, and is very repeatable on my end. It happened in v20 beta and now in the official release as well.
This shows up in the rendered video as well so it isn't just happening in Davinci.
Here's a loom video of it too
https://www.loom.com/share/75779c29295e ... e98d1e50da