I was going to start a new post but this one is very similar.
I too have been experiencing movies and shows being limited to 720p (US). This seems to be related to H264 with both MP4 and MKV. When I select H265 I have better size options.
A few weeks ago I was downloading movies at 1080p for MP4, so I’m not sure what changed. I believe I was even using the same version of SF when I noticed this issue. I even tried going back several versions, but the results were the same.
Ideally I would still prefer H264 for compatibility.
I can upload a log file if it would be of help.
