I’ve just noticed that on my site: https://girlswithguns.org
At the top left-hand corner of the custon slider, is a mini-thumbnail version of the slider image in the top-left corner. This doesn’t appear on the first slide, but appears just before it cycles to the second slide.
It works fine when there is one custom slide, but the thumbnail appears if I add a second slide.
I’ve disabled CloudFlare caching and also WP Super Cache in the application, but the issue persists. Any thoughts on a cause/solution?