The user journey is:
I presume unchecking this box should update preferences - can a Shopify Expert please confirm, and advise how to investigate this further?
Have you made any progress on that mater?
I notice the same problem on my store. It means that you can't unsubscribe, it's very annoying!
I'm looking for a 3rd party app that could maybe help with that. For the moment I'm using Mailerlite to send newsletters to customers accepting email marketing . It's adding another problem: if customer unsubscribe via the link in the newsletter it's not updated on shopify. Which also means that if this customer want to subscribe again, he can't, because at Shopify level he is still registered as a subscriber...