I'm using a different apple ID now. So I switched accounts like this: - I signed out of the old apple ID in System preferences > iCloud. Then signed in with the new one. - I signed out of the old apple ID in App Store > Store. Then signed in with the new one. - I de-authorised the old apple ID in iTunes > Accounts menu > Authorisations. Then authorised the new apple ID. I restarted the computer.
However, even after authorised the new Apple ID, it's the old one that still shows up in iTunes > Account, on top, even though it has already been de-authorised: Screen Shot 2017-11-05 at 16.56.55.png not only that, now, when I go to Account > View my account, I'm prompted for the old apple id and password, and if I use instead the new one, it won't go through, I'm prompted again for the new apple id and password.