Zoom in

After editing a HTML/Canvas file in Animate CC, the zoom in (Z) generates a skewed image which I can't edit, click "Fit in Window" shows normal. Also setting a smaller width W=500, the problem disappear. Same for 20.0.2 and 21.0.

Note: Can't attach the test file in this post, it says

• The attachment's zoom_in.fla content type (application/octet-stream) does not match its file extension and has been removed.

Link for the test file (zoom_in.fla):

https://drive.google.com/file/d/1kHe9akgyxfNk3d4N6DmNUwisj0fBa9Zu/view?usp=sharing