Why does command line text selection hang the running application?

We have an application that displays registration information on stdout

. However, if it is running in a command prompt window, you can use Mark to select text from the console. If you leave the selected text, the application simply freezes and does not jump until you deselect the text (for example, press Enter to copy the selection to the clipboard). After that, the application continues to work normally. Thus, it acts exactly like a breakpoint.

Could this command line behavior be disabled somehow?