Harry and William are said to still be at war following the Oprah Winfrey interview.
But the brothers will be forced to put on a united front temporarily when they attend the unveiling of a statue to their mother Princess Diana at Kensington Palace on July 1.
The siblings commissioned the statue in 2017 to recognise Diana’s “positive impact in the United Kingdom and around the world.”
After a number of delays caused by the pandemic, the statue is to be unveiled on what would have been Diana’s 60th birthday.
It’s being installed at the Sunken Gardens, which was Diana’s favorite spot in the grounds of Kensington Palace.
Prince William and Prince Harry will both be present at the occasion – their first meeting since Philip’s funeral in April – but Harry’s wife Meghan will stay home in California to look after their new daughter Lilibet Diana Mountbatten-Windsor.
The brothers have declared a truce for the ceremony – but there are no signs of any permanent reconciliation, the Sun reported.
The two princes will leave Kensington Palace together, walk to the statue and then deliver their own speeches.
A source told the newspaper: “The boys will walk out together out of respect for their mum but there’s been no reconciliation.
“Charles will leave the boys to it. Harry will need to quarantine for at least five days when he lands in England, most likely at Frogmore Cottage in Windsor.
“Charles has made it quite clear he will not be around beyond that because he is going to Scotland. There is no planned meeting.”
Harry and William are said to have communicated only by “a very brief and minimal exchange of text messages” since the Duke of Edinburgh’s funeral.
The source added: “The relationship is still very much strained and there’s no sign yet that there will be any sort of coming together any time soon.”