However, after a whirlwind 24-hour trip from California to see his father in early February, Prince Harry did hint that future visits were on the cards.
The duke flew 8,000km to the UK without his wife Meghan Markle and their two young children Prince Archie and Princess Lilibet after it was revealed that the monarch had been diagnosed with an unconfirmed type of cancer.
In an interview that same month with ABC's Good Morning America, the Duke of Sussex spoke of how "any illness, any sickness brings families together".
"Throughout these [Invictus Games] families I see it on a day-to-day basis, the strength of the family unit coming together."
He then added that he had trips planned in the future that would take him back to the UK, "so I'll stop in and see my family as much as I can".
In the same interview, Harry revealed that Charles shared the health update with both his sons personally, whereafter Harry flew straight to London.
"I love my family, the fact I could jump on a plane and see him and spend any time with him - I'm grateful for that," he said.
A day after Buckingham Palace made Charles' cancer diagnosis public on February 5th, Prince Harry arrived at his father's royal residence, Clarence House, where they spent 30 minutes together.
Charles and Camilla then departed to nearby Buckingham Palace where they then helicoptered to Sandringham Estate in Norfolk.
The monarch reportedly delayed his helicopter leaving by an hour so he could see his son face-to-face for the first time in more than 16 months, their last meeting taking place when Queen Elizabeth II died in September 2022.
While aides have not yet confirmed how the Duke of Sussex reacted to hearing the news of his father's ailing health, his last minute decision to fly home does suggest that the bond between the father-son duo, whilst at times strained, remains strong.
Given the duke's former UK residence, Frogmore Cottage, is now the home of Princess Eugenie, her husband Jack Brooksbank, and their two sons August and Ernest, it is expected that he stayed overnight at a luxury London hotel before jetting back to his home in Montecito, California.
When he last visited the country in September 2023 for the WellChild Awards, the royal was made to stay in a hotel after his request to stay at Windsor Castle was denied by the royal family due to the "last minute nature" of the request, according to royal sources.
During that same trip, Harry was also unable to visit his father who was holidaying at Balmoral Castle due to scheduling conflicts.
Given he and Meghan were stripped of their right to automatic police security in the UK after they stepped back as senior royals, the duke travels with a private security entourage when visiting home.
It is currently unclear what the state of the relationship is between the king and his youngest son, Harry.
After a fleeting appearance in London for King Charles' historic coronation on May 6th 2023, Harry and his father have reportedly barely spoken, save for a handful of telephone conversations.
Buckingham Palace did not publicly celebrate Prince Harry's 39th birthday on September 15 2023, but the Duke did allegedly reach out to his father to wish him a happy 75th birthday in November that same year.
It is understood that the king received a video of his grandchildren singing Happy Birthday to their grandfather and that Meghan also spoke with her father-in-law.