As title, every time I try to 'Pair Device' on the Meta Horizon app, it prompts me that the email address is associated with an Meta account, please log in or try another email address. BUT, I have already logged in as the email I entered there.
Make sure you clicked the correct "log in" link, as it sounds like you might have accidentally clicked a link to register a new account instead of logging in, and can't, because you have already registered a Meta account using that email.
If you're talking about the mobile phone app, then try restarting the app. Open your web browser and log in to Accounts Centre using your Meta account details and see if that helps. Or maybe try logging out of the phone app, then log back in.
If you are talking about the Meta Horizon Link PC app, make sure you log in via the big blue "register/log in" rectangle, not the "have an Oculus account? Log in" link beneath it. If you are setting up a new headset, I'll also point out that you must set it up using the phone app, not the PC app (some people get confused by this).
