Images: Lock aspect ratio not working

Replication Path
1) Drag an image from Windows Explorer onto a MS measure
2) In the Image section of Inspector, tick the box for "Lock aspect ratio"
3) In same section of Inspector, increase the Width value

Result
The image distorts because the Height is not automatically adjusted to match the increased width and therefore the aspect ratio has not been locked.

Platform
MS 3.4.2 on Windows 10