After a site pops up multiple dialog boxes, some browsers will give the user the option to prevent additional dialogs from the page.
This is what this box looks like in Chrome:
This is a feature of the browser, not of mutwatch.
If you accidentally check that box, then additional confirmation dialogs will not be displayed. This will prevent you from being able to use the Remove from Binder option or Redeem a Set - because those functions require you to affirmatively answer a confirmation.
In order to reset that option, you must close your browser window. If closing the browser window does not work, then close ALL open browser windows. Then return to mutwatch and the dialogs should be working again.