a number of Sony TVs can't view 1080i @ 50hz correctly. XE8596, XE9005 and probably some others are affected, which you can see a huge thread at AVForums discussing it at length - https://www.avforums.com/threads/sony-xe90-frame-repeats-drops-on-50-59-94-native-content-49xe9005.2...

Sometimes a stutter can be observed as soon as the camera changes. The only workaround is to use game mode, but this is unacceptable for a premium TV as a lot of television programmes in the UK is broadcasted at 50hz. Why hasn't it been fixed? Absolutely shocking I paid £900 for a larger TV that comes with faults, when an other brand TV I purchased in 2011 for £300 does not have this issue.

I have uploaded a slow motion recording showing this, you can see it at 0:03 and 0:16 seconds.