Facebook has quite a few settings to protect your subscribers' privacy - this is one of them
If you check Recart Messenger campaigns from your Facebook page inbox, some of the buttons in them will show up as 'Disabled', and you won't be able to click them, just like here:
Don't worry though, nothing's wrong with your campaigns, this is just one of Facebook's privacy settings. 👌
Facebook disables these buttons on the Facebook page owners' end to avoid giving away sensitive information.
This means that the buttons in your Messenger Campaigns are only clickable for the person who receives them. 👍