Amazon + inputstream on pi

Hi
What are people’s currently experiences of trying to get Amazon prime video working on pi? I have sandmann’s addon mostly working now on a milhouse build. Films play as do most tv series. I just find that current tv series which release a weekly episode only give sound (no picture).
Seem to be getting 1080p now as well having experimented tweaking the Inputstream settings (well codec info is saying 1920×1080 anyway!)