To clarify this, if you load an image into the canvas, and it is from either a different domain, or the local file system (ie: file:///) then it will "dirty" the canvas, which prevents the pixels from being read. EaselJS uses pixel fill to determine mouse interaction.
Colin's suggestion is right -- check the console to see if an error is raised when you click the element. Running on a local server (which Adobe Animate does for you when testing) will get around that. There are other things you can do to prevent the error, but first you should determine if this is causing your issue.