Hi James! I hate to hear that you're frustrated, but I'd be happy to help here.
When I tested this, I was able to use the cut function, but could not paste data into the HTML editor. I'm going to loop in my technical team for further insight here -- in the meantime, are you able to use a different browser? I was able to work without interruption in Google Chrome, for example.
I will be back in touch with more details shortly!