Had a play with the HDR feature. I loaded 5 Pentax RAW files. Once Affinity had finished processing, I selected the high contrast black and white option. So far, so good.
I then applied the Dodge brush to emphasise a line of mist in the landscape. If I then export to jpeg and resize the image, I end up with some cyan dots near, but not under where I used the brush. (jpeg quality 95%). This doesn't happen when not re-sizing, and when I didn't first use the dodge brush. If I recall correctly the problem remained even after I had gone back on the History tab to before using the Dodge brush.
I tried to attach the original sized jpeg - not sure if it attached or not