Not sure what happened but using the web:
I then tried using the chrome extension:
My phone app has consistently been working throughout which makes me think that there is something that is confused with my account settings (free vs. family) at Lastpass that is kicking me out every time on the web app.
Could you try uninstalling the LastPass extension, clearing your browser's cache, then reinstalling the extension from here to see if you can then log in to LastPass? https://lastpass.com/download/
This still did not fix the issue. I don't want the extension installed either. I was just using the web browser up to this point. The only reason I installed the extension was that people had said this made the vault accessible (which it did). I am apparently experiencing the same issue as these people
We've done a refresh on your account, could you try restarting your computer and trying to log in to LastPass at https://lastpass.com/?ac=1 again? If that doesn't work and you're still seeing the login screen after logging in, is this happening in other browsers as well, or only a certain browser?