This is happening to me as well on Google Chrome from my Microsoft Surface.
I'm much more concerned about Lastpass' lack of response on this issue vs. the issue itself. Does not speak well for the support of their product.
Maybe it's time to revisit my Password Management solution. I've been a member for years, but I've never seen anything like this before. SAD!
UPDATE: I had to go into my Lastpass Vault to add my site. This is not the streamlined, integrated and efficient solution that I have accustom myself to