I followed the very clear instructions to make sure I wasn't missing anything, and I had set up the add on correctly. Still, it straight up blocked a site, although I had set it up to block me after 30 minutes. It's a very easy to use system, and I am 100% certain that I didn't tell the add on to block me- I set it up to block me after 30 min in a day. I hadn't used the website at all yet today. The grayscale filter also produced an intolerable level of lag that resolved when I removed the add-on. I installed a similar add on that was able to allow me limited access to the target website.