Meghan Markle and Prince Harry are reportedly at a standoff over their summer plans, with insiders claiming the couple had a major argument just before Meghan's trip to Geneva. It's reported that the row centred on Harry's plans to spend time on royal family turf this summer, including a proposed stay at Balmoral, which Meghan is said to be strongly opposed to.According to Heatworld, the argument took place hours before Meghan flew out to Switzerland, and that the couple did not speak for some time afterwards. Wonderwall can reveal that the strain between the Sussexes has increased significantly in recent weeks, with insiders describing tensions as "off the scale" ever since.What the argument between Meghan Markle and Prince Harry was aboutAs per the reports, Harry had been "getting incredibly sentimental" ahead of their eighth wedding anniversary while also trying to plan a family summer in Europe. "He's carving out time at Balmoral, so his father King Charles can see Archie and Lilibet." the report said.But Meghan is allegedly unhappy with the plans, particularly given the ongoing tensions with Prince William and Kate Middleton. The relationship between the four, once dubbed the Fab Four, has been strained since Harry and Meghan stepped back from royal duties in 2020. The last time all four were seen together was at the late Queen's funeral in September 2022."The plan for Harry and Meghan was to base themselves in Portugal for the summer, then spend time in Balmoral. But Meghan has heard that William and Kate have told Harry the Sussexes are 'not welcome' and they refuse to have their family sanctuary disrupted by what they called 'Hollywood drama,'" the report added. "Meghan flipped, and a normal argument turned into a showdown. Tensions are at an all-time high."Meghan Markle's Switzerland trip and anniversary celebrationsShortly after the disagreement, Meghan headed to Switzerland to attend the installation of the Lost Screen Memorial at the Place des Nations in Geneva. The memorial, created by the couple's Archewell Philanthropies, features 50 illuminated lightboxes displaying the lock screens of young people who lost their lives to online violence and digital harm.Despite the reported tension at home, Meghan went all out on social media for their eighth wedding anniversary upon returning to California. Sharing pictures and videos from the kitchen of their Montecito home, the couple sang a happy anniversary song to the tune of 'Happy Birthday' alongside their children Archie, 7, and Lilibet, 4. They also shared a kiss before blowing out the candles of a lemon elderflower cake, the same cake they had at their 2018 royal wedding. Meghan also reacted to a sentimental penguin sculpture from Harry, inspired by their 2017 engagement party costumes.The former 'Suits' actress then shared two Instagram carousels of previously unseen photographs from their Windsor wedding, writing beneath both, "Eight years ago today."Where things stand between Meghan Markle and Prince Harry Despite the loved-up anniversary posts, insiders say the couple remain at a standoff over their summer plans. "Meghan's bust-up with Harry was a big one, and she's digging her heels in. She's told Harry to go to the UK without her, as there was no way she would be joining. She doesn't want to put herself, or the kids, through the drama," the report stated.With Harry keen to reconnect with his family in the UK and Meghan reportedly unwilling to set foot on royal territory amid the ongoing tensions with William and Kate, the couple appear to be heading into the summer with a significant disagreement still unresolved.