I’ve never seen that happen before, and I’m not exactly sure what’s causing it to do that.
If I add width: 100%;
to html > body .slide-excerpt-border
in the CSS, then it sort of fixes it.
Also can be fixed with word-wrap: normal;
I’m not sure if that is a Plugin issue that StudioPress will need to take a look at or if the issue is coming from the Child theme or another external source. Either way, the above suggestions should be able to fix it, and you can add additional CSS for the padding/margin to adjust the position it shows up.