The blunder came as the show covered the first glimpse of Archie along with the Duke and Duchess of Sussex last week.
Above the subtitle, "They showed their first-born for the first time," were the words "Harry Styles y Meghan Markle," meaning Harry Styles and Meghan Markle.
A screenshot of the show's mistake was immediately shared on social, and proceeded to be posted by others.
Most of the reaction focussed around Harry Styles' fans laughing at the faux pas.
Styles himself has not commented on the post.
At the same time as Styles was apparently being outed as Meghan's husband, he was preparing for the annual Met Gala ball in New York.
Styles set crowds alight with his sheer blouse while donning a pearl earring.