Katie Nicholl, Vanity Fair's royal correspondent and author of Harry: Life, Loss, and Love, told ET, "It's absolutely the case that the brothers did fall out. I was told by a very senior royal source that actually they weren't talking to each other at one point."
However, thanks to a new royal addition, she thinks they could be on the mend.
"I certainly think now that Archie is here, it has probably really helped to improve the relationship," she added. "William is over-the-moon that his brother is a dad."
The Sun's royal reporter says while the couples saw each other in public settings, they did not see each other behind closed doors: "I was told, after the Royal Wedding, Harry and Meghan didn’t see Kate and William personally."
Andrews added, "I think behind the scenes, Harry and William’s relationship has always been up and down actually but of course, we’ve never really seen that."
However, the worst of the feud seems to be over with the two princes reportedly making progress in their relationship. Prince William and Kate Middleton visiting the Sussexes recently after the arrival of baby Archie.