Two ideas, neither guaranteed!
First, try resetting the tools. With your Crop Tool selected, to to the Options Bar. At the far left will be the icon for that tool. Click and hold, and you will see options to either Reset that tool or Reset All Tools. Try this one first to see if it works.
Second, delete the Elements Preference folder, in case a corruption is causing the problem. With Elements closed, click on the start up icon and then quickly grab for (Win) the Control, Alt, and Shift keys (Mac) Command, Option, and Shift. Hold all three down until you see a screen asking if you want to delete Settings. Say Yes.
Try one or both of these to see if the Crop tool again starts behaving properly. If not, repost and let us know you've already tried. Somebody will come up with another bright idea.