@paulgarmeson
If the new account was unintentional, and using a different email address, you may delete it at any time via this method + email confirmation.
If this is just an instance of the Vault appearing empty on one device, while using the same LastPass credentials, then it could be a sync or cache issue within LastPass itself.
HELLO! @paulgarmeson
Welcome to the LastPass Community.
We are sorry for the problem with your browser extension and the autofill feature.
We need to make an investigation to better understand the issue. I will recommend you create a support case so one of our support agents can help you to find a solution for this behavior. You can create the support case using the steps below:
We apologize in advance, please let us know if there is something else, we can do for you.
Greetings!
Verlaine | Customer Care