This is just a glitch in the recent update. It’s actually appearing “underneath” so when you go to click, it’s hitting the page that’s on top of it. The workaround at this point in time is not to click. So hit the button to Add Site but then you just used your keyboard to type things in, Tab to switch between the Name and URL bar, then hit Enter for it to accept.
It’s implemented…you’re linking things from over a year ago. Stuff changed.