I tried Amazon Prime briefly, for the trial. OMG the content was so bad, straight back to Netflix. Anyway, I remember this issue coming up at that time and I tried to view an Amazon video through my web browser (Edge) and it worked fine? Just like it does with Netflix? Have you tried shifting to desktop mode in the web browser settings? If the web site keeps pushing you to use a non-existent app instead of playing the video on the site, this trick often gets around that issue.