Extension XCarousel 1.3, click "Add new slide" not working on XWiki LTS 12.10.10

Extension XCarousel 1.3, click "Add new slide" after the default first three does not work.  It tries to add a slide, but it is named Slide 3 same as previous one, task will not complete. 

First posted issue in XWiki Forum (https://forum.xwiki.org/t/extension-xcarousel-1-3-click-add-new-slide-not-working/9611) and received a workaround.  Found during my implementation and first real use of this extension.  Haven't even tried adding caption title or text or even any other supposed functionality of this extension.