When I change the skew (with the yellow double arrow when hovering one of the four sides) makes a keyframe when I'm in Design mode, it doesn't animate just makes a keyframe.
It happens in all the projects I tested, both in Firefox and Chrome, here is one of the tests: https://editor.animatron.com/#p=02a7a458bb47ca7490191441
PS: I just signed up and am very impressed with your app and what it can do.
We know about this issue. We'll let you know when the problem will be fixed.
To avoid creating keyframes when changing the skew, please put the playhead to zero seconds.
Once again, sorry for the inconvenience.