Although I have used DIVI Builder to make posts, the text that is displayed on page 'xx' is the text of the extract, so it should not affect anything that has been done in the long description of the post.
Regarding the pagination, the funny thing is that in other CPTs I have not needed to include the pagination shortcodes in the loop or in the filter, maybe it is because in the archive pages it is not necessary, but in the views it is necessary.
Look at the screenshot.
It may be that the pagination controls on the archives are being automatically added by the theme, whereas when you create a View you must add the controls.
And regarding the nesting of Divi content inside templates designed with Divi, it is not the content itself that is the issue, it is the markup which Divi wraps around the content, rows, columns, containers etc.
I suppose that, as in other cases, the combination of the CSS of Bootstrap and the CSS of DIVI can also be the cause of paranormal circumstances.
Again, thank you very much for your help Nigel.