Hello,
When an article is created with SP Pagebuilder, and it is later moved to another category, the article is then only available in the default Joomla Editor. All the settings created with SP Pagebuilder are gone. You have to edit the article, click on SP Page Builder button, click on Save, and then it is okay.
It only happens when you batch move the articles from one category to another. When you move only one article in the article editor there is no problem.
Maybe it is a Joomla! issue?
Regards, Peter