Same. I do not have a solution but last pass is currently broken on brave.
Same issue on multiple machines that run Brave (Windows and Linux). No other Lastpass issues (full GUI, authenticator, Android, iOS), only the browser extension. Microsoft Edge using the same extension works fine.
LastPass doesn't work on Brave for me either. Uninstalling and reinstalling does not fix it.
Same issue... not working and using Brave. Started yesterday afternoon.