The publication claimed William had "reservations" about Harry's new wife and he told his grandmother, Queen Elizabeth II, of these concerns.
"The problem is that the Cambridges felt things had moved very quickly between Harry and Meghan. Wills particularly was worried and felt close enough to Harry to voice his thoughts," the insider said.
Later it was claimed Meghan's personal assistant Melissa Toubati quit after being "reduced to tears" by the royal’s demands.
A source told The Mirror: “Her job was highly pressurised and in the end it became too much. She put up with quite a lot. Meghan put a lot of demands on her and it ended up with her in tears.
“She is hugely talented and played a pivotal role in the success of the royal wedding. She’ll be missed by everyone in the household."
The news comes just after a royal insider claimed Kate was also left in tears at Princess Charlotte's bridesmaid dress fitting for Prince Harry and Meghan's wedding.
Two separate sources told the Telegraph Kate was "feeling quite emotional" at the fitting, which took place shortly after she gave birth to her now 7-month-old son Prince Louis.
However, Kensington Palace has since claimed the feud between the two royals as fabricated.