After downloading my paid version last night (Windows version, on a Asus UX490) I had no results using any available instructions over a 2 hour period. The only way I could get a vignette was if I loaded a unprocessed RAW file and the first thing I did was apply the vignette. No results at all with JPEG, TIFF, or any partially worked files.
Loading the same files in Photo Director 9, or ACDsee ultimate I was able to produce a vignette on the various files.
I love what I can do with Affinity Photo, and I really liked the quality of Affinity's Vignette.
What do we need to do to work around this flaw?