First i’d like to thank you for your time 😉
i changed imsanity settings to resize to 900×900 like in your video, and there is no bug…
in fact there is no bug, when imsanity resizes smaller than the large image in the media parameters of wordpress …
Try using my parameters :
large thumbs in media parameters: 1024×1024
resizing options in imsanity : 1024×1024
I just tried on a new installation, no plugin whatsoever…
theme is twenty fifteen.
i installed imsanity
Same bug
i disable imsanity, bug disappears !
when cropping go from a landscape to a portrait image