Think Up Themes – Pagebuilder

I have the Minamaze theme installed and is using Pagebuilder. When trying to copy a page (homepage in this case), you click on “Insert per-built page layout”. It is supposed to show a list of all pages in my wp. It shows only three!
I’ve submitted a support request with Think Up Themes and got the following reply:

“I’ve taken a look at your site and I can see that the only pages available in the pre-built layout are those that you have created yourself. If the pages are not showing then this is not an issue with the theme, it is an issue caused by either a restriction on your site placed by your host or a 3rd party plugin that has prevented WordPress metabox data from being stored to your database.

We can only assist with theme specific issues. Not issues caused by 3rd party code or server configurations.”

Can anyone PLEASE give me some advice / pointers as to where and how to fix this?

Much appreciated!