For weeks on end, after installing Ubuntu 18.04 LTS (Bionic Beaver), LastPass panel icon would not allow entering the password there. Each power up, I would click the tiny icon, but the small window would not stay open. I had to "manually" enter http://www.lastpass.com
and then login.
I have reverted the Gnome Manager to Unity and now LP is working as always. If you wish to do the same, here is a write up on the steps I used to change back to the Unity Desktop/Display Manager. It is simple.https://linuxconfig.org/how-to-install-unity-desktop-on-ubuntu-18-04-bionic-beaver-linux
By the bye: GnomeDM also broke my HP panel display icon as well as doing some harm to the printer sub-system.