It currently has a bug that causes it to trigger sometimes when I click the back button. I just visited the page a minute ago, it works fine when the addon is disabled, and my internet connection is fast, so I don't think it's a problem with the site.

However, apart from the bug, this is indicative of a problem with the addon design, which is that it redirects to a different page, and offers no option to exit out of the addon or try to load the original page even if the Wayback Machine addon thinks it's broken. It's okay for the addon to make mistakes, it's not okay for me to need to disable it in order to load the original page.