WP Testimonials have problems with Theme X

I really like WP Testimonials, seems the best of those I have tried. However on one site I am using Theme X, and WP Testimonials starts to do strange things when Cornerstone is installed, and Themeco says cornerstone is needed for X to function properly (WP Testimonials works fine until cornerstone plugin is installed).

Just wondering if anyone knows how to fix this problem? The testimonials no fit nicely in the sidebar, parts of words are missing on the sides, and the navigation buttons are screwed up and way down the bottom instead of at the sides of the testimonials. This can be seen at https://www.bendigodogtraining.com.au/wordpress