This looks like your browser still caches the JavaScript of earlier times. Unfortunately, most users won't flush the JS cache, even if you request to clear all browsing data...
Try closing the browser altogether and restarting it.
Another possibility is to go to the "Developer Tools" (press F12), go to "Network" and select "Disable cache" (might be named differently depending on your browser). Then reload the web interface of Pi-hole and keep the Developer Tools opened. The first loading might be slow (because no caching will be done), but hopefully it works in resolving your issue.