A Buckingham Palace statement said at the weekend that Harry and Meghan would still be referred to as Duke and Duchess of Sussex, but now this reportedly is under review.
Palace sources told Sky News that the couple's titles are being looked at again as it appeared Meghan has been given the title of a divorced woman.
This is because of the comma - as Meghan would be known as Meghan, Duchess of Sussex.
Previously, Diana was known as Diana, Princess of Wales following her divorce while Sarah Ferguson took on the title Sarah, Duchess of York after her break-up.
Sky's events commentator Alastair Bruce said: "The palace made an announcement about what the duke and duchess were to be called.
"But it inadvertently gives all the wrong messages because, in convention, the style suggested is the one adopted to express divorce.
"As a result, this will be revisited and I'm sure that the expert, called Garter King of Arms, can provide advice.
"What had been suggested was 'Meghan, Duchess of Sussex' but placing the first name and comma before the title is the template for a divorced wife.
"As an example, Harry's mother was styled after her divorce as 'Diana, Princess of Wales' and the same format applies, post-divorce, to 'Sarah, Duchess of York'.
"I fear that eight years giving advice to Downton Abbey makes me eagle-eyed for such things."