I'm very sorry for any inconvenience this may have caused you. Could you please try the following troubleshooting on your browser:
Have a wonderful day and take care!
I had the same issue on Macos Chrome - latest OS and latest Chrome. I had updated the Lastpass Extension following the remedy #1 directions on the support site (turn on developer mode click update). After following those directions the issue had started.
The above steps resolved the issue.
Side note: I had also encrypted my URLs as per the required update. After this the previous plugin would not return search results. Going in and telling it to refresh the vault worked until I restarted the browser. Hopefully this is resolved with the new version.