Post loops pagination (load more button) & Not a valid JSON response [ISSUES]

Hello,
I’m writing because of two problems we’re getting in a clean Newspaper installation:

1) In the category template we have included a post loop block to show all the child articles with a ‘load more’ button, but when we click on it, the new set of loaded posts is exactly the same group of articles that were already shown. This happens with any kind of pager: conventional paging (1, 2, 3…), next/prev AJAX buttons, and load more button (this last one is the solution we want to use).

2) When updating a post already published we get a message “The response is not a valid JSON response”. Specifically, we were trying to set the main category of each post in the template selector.

We’ve updated to the latest version of WordPress (5.4) and Newspaper (10.3) but the problem remains. We write an email to contact@tagdiv.com with the access to the site and the details aswell.

Thank you.