I followed those steps and now I have a different problem, on all three browsers.
The Kaspersky Password Manager extension icon is grey, and when I click it I am prompted to enter in my main vault password. When I do this, I get a message "Incorrect main password" but my password is definitely being entered in correctly. I validated this by accessing the vault via my desktop shortcut.
I cannot see what userid the extension is trying to use, though.