testimonial slider cut off at bottom

I placed a testimonial slider in the sidebar, but part of the testimonial is cut off at the bottom and no author is showing. When I did an inspect element, I can see that there is a static height applied to it via “bx-viewport” but I can’t figure out how to change this. I tried the testimonial slider widget with adaptive height as well as the shortcode:[testimonials_slider adaptive_height="true"] but neither of them works.

When I removed the top padding from my sidebar, the bottom of the testimonial was visible, but I need that padding. Have an other ideas?

How do I get rid of the fixed height?