Steps to reproduce:
1. Create a new slider and select it as the slider in Dokan settings
2. Enter title and text and enter a title and select an image, and click Publish.
3. View the home page – one slide is visible
4. Add another slide using the same steps and click Update
5. View the home page – first slide shows up once, second slide shows up twice
6. Add another slide and click Update
7. View the home page – first slide shows up once, second slide shows up twice, third slide shows up 3 times
Any ideas? I just created a child theme; I didn't try this before creating the child theme. Right now the only thing the child theme folder contains is the style.css file.
I'll post a private reply with the URL to our site so you can see.