I think the title says it all. Normally when I open Chrome I get the loginscreen for lastpass. Since a couple of days I get the vault where I have to login, although in options the square for opening the vault after log in is not ticked
Not sure what you mean. Sounds to be there is no difference, since in both instances it sounds like you are required to login.
Scenario 1: Open Chrome I get the login screen for lastpass.
Scenario 2: Get the vault where I have to login