Pages

I have the theme iFeature Pro 5 and yes I know where their support page is and it is not helpful so please do not say anything about their website. I have a ton of pages on this website I am making for my client but every time I go to add a new one to the menu, it will not add them. I have about 100 pages on the menu but most of them are sub items, yet it still will not add anymore. Can anyone help me with this. My website is https://www.iamwelladjusted.com/. Thanks in advance.