Hello @aphonic! 👋
I'm sorry that you're seeing duplicate items in 1Password. We do have an open feature request for a tool that would allow users to merge items and, while I can't make any promises, I've added your vote there so that our product team is aware that this is something that you'd like to see.
For the moment, the best option is to make sure that you have a Login Item for that website/account that contains all of the information that you need to keep. Then you can delete the other items.
Thank you for the suggestion. 🙂
-Dave
ref: PSS-I-25