Prince Harry and Prince William's relationship are still tense as the brothers will reunite for the coronation of King Charles.

“Things are strained,” a palace insider told PEOPLE.

“I don't think the coronation and a big conversation can be conflated,” said the insider.

In Prince Harry's memoir Spare, which was released back in January, the royal detailed an intense physical altercation between the two in which Prince William called his wife, Meghan Markle, “difficult,” “rude,” and “abrasive.”

“He grabbed me by the collar, ripping my necklace, and he knocked me to the floor. I landed on the dog's bowl, which cracked under my back, the pieces cutting into me. I lay there for a moment, dazed, then got to my feet and told him to get out,” Prince Harry wrote.

Prince Harry reiterated their issues before Spare's release day in an interview with ITV's Tom Bradby.

“There's a lot that can happen between now and then. But the door is always open. The ball is in their court,” he said. “There's a lot to be discussed, and I really hope that they're willing to sit down and talk about it.”

Just recently, it was announced that Prince Harry would not have Meghan Markle by his side during his father's coronation.

“At this point, it's become so personal,” a close friend told the publication. “Maybe what they wanted wasn't achieved, but at the end of the day, he's going there to support his dad.”

King Charles' coronation will be on May 6.