CharlesCaplan
Thanks for the reply. In most cases, there's no need to clear your browser history regularly. Was there a specific reason why you do so? The primary benefit of clearing your browsing history regularly is to hide it from someone who might have physical access to your Mac and might want to snoop on what you've been doing online.
When clearing Safari's browsing history you'll also clear 1Password for Safari's local data, Safari web extensions (of which 1Password for Safari is one) store configuration data in the same bucket that Safari clears when you choose to clear history/cache. Clearing Safari's history/cache will reset 1Password for Safari's preferences and result in you seeing the prompt that you reported seeing again.
Other browsers, like Chrome and Firefox, don't clear extension data when you clear browsing history so moving to one of those is also an option if you'd like to keep clearing your browsing data regularly.
-Dave