Meghan Markle and Prince Harry have been criticized for giving Prince William a "cold" and "useless" birthday message.

On Friday, the Duke of Cambridge celebrated his 37th birthday. A number of royals fans sent their warm birthday wishes to the future king. Prince Harry and Markle did the same, but the netizens weren’t pleased on how the couple did it.

“Happy Birthday to The Duke of Cambridge!" Prince Harry and Markle commented on a post on Instagram.

A number of online users slammed the new parents because they have been penning less formal messages to the other members of the royal family, but they sound so formal to Prince William.

“Such a cold birthday wish. That's confirmation right there that something unsettling is going on between Meghan and Kate. The brothers and Kate were fine until Meghan. Very sad, indeed,” one netizen wrote.

“@sussexroyal well well well, what a cold happy birthday,” a different user commented.

“@sussexroyal wishing your brother just like this is so useless sharing a photo with a kind message would be so nice,” another follower wrote.

A different online user said that it seemed that the Sussexes didn’t sound like they want to wish Prince William well on his birthday.

Prior to Prince William’s special day, it was announced that Prince Harry and Markle decided to split their charity from the Duke and Duchess of Cambridge. Initially, Prince William, Middleton and Prince Harry founded the Royal Foundation.

Markle joined in after dating the Duke of Sussex. However, recently, Prince Harry and Markle decided to create a new charity and focus on it.

Royal commentator Duncan Larcombe didn’t understand Prince Harry and Markle’s move. He questioned why they have to separate their charities when the fab four are backing the same causes. He added that while this move isn’t conclusive of a rift, it’s a definite sign of “division.”

Larcombe also said earlier that Prince Harry and Markle’s move to hire a separate media team confirmed that there’s a falling-out between the fab four. He believed that “things aren’t going so swimmingly for the four of them” and added that it’s a sign that they are living in a different place and are not the best of friends.