Selecting categories does not work

Hello,

I’m trying to use Recent Posts Widget Extended by selecting a category to display posts of, but it doesn’t work. No posts show up, at all. Category is not empty. When I try to select a category by the multiselector, it works fine, but upon reload not a single category is selected.

I use Page Builder (http://ww.wp.xz.cn/plugins/siteorigin-panels/) where I try to put the RPWE inside one, but as I mentioned, it doesn’t work. Any help?

https://ww.wp.xz.cn/plugins/recent-posts-widget-extended/