these are the two media queries

use a higher value for screen max-width (960px and 800px)

@media screen and (max-width: 960px) {
#wpforo #wpforo-wrap .wpfl-4 .wpf-thread .wpf-thread-forum-mobile {
display: block;
}
}
@media screen and (max-width: 800px) {
#wpforo #wpforo-wrap .wpfl-4 .wpf-thread-box.wpf-thread-forum, #wpforo #wpforo-wrap .wpfl-4 .wpf-threads-head .wpf-thead-forum, #wpforo #wpforo-wrap .wpfl-4 .wpf-thread-box.wpf-thread-status, #wpforo #wpforo-wrap .wpfl-4 .wpf-threads-head .wpf-thead-status {
display: none;
}
}

add it to custom css
Dashboard > wpForo > Settings > Colors & Styles > Custom CSS

Thanks a lot