Harry is determined to force his father to grant him the security he thinks he is entitled to, as a 'Prince of the Blood' as he once described himself.
Charles, I think, is equally determined not to be blackmailed; I suspect he is nor that bothered about seeing his troublesome son, and if it means yet another postponed meeting with his scarcely known grandchildren, so be it. Meghan doesn't really enter in to it, although I doubt she believes that.
It is very clear Harry has very little else to do.