I got an even worse version of the same problem...
I did just buy Affinity Photo 1.9.1.1979 and I almost hate the extremely bad experience, compared to Corel PhotoPaint x4 - which unfortunately not work with Windows 10 in my new laptop...
*** And the worst was when I found that every photo I finally did manage to edit, got an extra white line at one side (about one pixel wide) except the last photo which got extra white edge lines at BOTH sides!
I show here the two first and you can see the thin white edge at the right side, on a black backround... But I manage to redo the last photo, which in addition got blurry at some of the ordinary edit stages - but it was possible to undo back to a clear photo and then export that one, without the strange extra white edges, even if I don't know why...
Okay I only manage do edit 3 photos and just very basic, after 5 hours (!!) which would take max 10 minutes in CPP x4 mainly because AFF is missing tons of helpfull icons / tools - as six direct Zoom and photo view % buttons, Undo and Redo icons (which work for every action) Resize photo icon, Curve icon, Colour correction icon, Set black and white point icon, Hide / Show Mask icon, Save as icon (to smart dialog window) and many other direct icons... So I was forced to do 3 to 6 extra steps before I could do anything, over and over again...
Just making one single copy of a photo and name it take 10 steps in AFF (open Edit menu, move the arrow and select copy, open File menu, move arrow and select new from clipbord, open file again, move arrow and select save as, plus select finally a folder to save the copy) before you can write in a file name and just 1 steps in CPPx4 (click the Copy icon) to do exactly the same thing!!!
And I did only cut the photos, resize to 1080pixels height, adjust curves, add some sharpness and "export" to hiQ jpg, because it was impossible to simply save to anything else than the AF format...
Every step was a lot more complicated, even if AFF did offer less options (almost everywhere, except of many extra ways to resize, but 3 of them gave horrible results) and you have not even a decent preview of the jpg quality, only a big thumb that was completely useless!
