I actually figured out my problem after replying to your original comment. There's some issue with DNS over HTTPS, so you have to whitelist their sites in your settings, or turn off DNS over HTTPS (which I don't recommend).

To whitelist, on Firefox: Hamburger menu > settings > privacy and security > DNS over HTTPS > Manage exceptions > Add "archive.is", "archive.ph", and "archive.today"

If you don't want to do that, or it doesn't work, use Firefox's reader mode or the google cache bookmarklet I added below.

Google Cache Bookmarklet:

javascript:void(open("https://webcache.googleusercontent.com/search?q=cache:" + document.location))