This extension has been broken for weeks. Apparently, they've removed the local vault and now it loads the website, but it breaks if you've visited the site in the past and have old cookies stored. Also, judging from the Chrome version, they've broken something in site detection and now it's more likely to fail to detect your existing entries and prompt to create a new entry when you log in or update your password.

Mandatory online mode, broken features and total lack of interest from the company suggest this is not a good nest to put your eggs, esp. considering that this company is well known for tracking user data, suffered a data leak affecting user vaults, and there're several competitors that offer much better value even in their free tiers.