However, a palace insider scoffs at the suggestion the royals are insulting Archie.
“Harry spent the whole day playing polo when Archie turned 3 years old last year,” reveals the source.
“Archie and Lili are too young for a drawn-out, formal occasion like this. Charles was 4 years old at his own mum’s coronation and he remembers it being dreadfully dull. He would have preferred being anywhere else, and imagines Archie would feel the same way,” says the insider.
This isn’t the first time the royal family has ‘snubbed’ Archie and Lilibet; just a few months ago, they didn’t turn up to Lilibet’s christening.
Sources close to the Duke and Duchess of Sussex claimed King Charles, Queen Consort Camilla and the Prince and Princess of Wales were invited but did not attend.
WATCH: Prince Harry's cute tribute to Lilibet in travel ad cameo
Instead, the almost-2-year-old princess was christened by a Hollywood bishop under the swaying palm trees on Harry and Meghan’s Montecito estate overlooking the Pacific Ocean, on a cold but sunny winter’s day.
Lili’s godfather, Hollywood bigwig Tyler Perry – who accepted the role on the condition that the christening was not held in the UK – jetted in for the ceremony, along with other famous faces including talk-show royalty Ellen DeGeneres and Oprah Winfrey.
“It was wonderful,” says a source. “There was cake, and games for the kids. It was a festive atmosphere despite being a small gathering.”