The slider of this theme has multiple problems. When you check in the firefox browser more tools and responsive design mode, you will find out the problem.
1. I find the slider button read more keeps disappearing in some devices. It looks ok in the landscape on some devices. But portrait mode looks like a problem.
2. The slider arrow button is missing on some devices.
Please kindly can you inspect yourself and adjust these CSS issues.
I am testing on localhost wampsever. I am not using wordpress.com or hosting services.
If you require screenshots, i can provide them. I am using the WordPress app from in localhost wampserver. Please kindly can you inspect your demo and adjust these CSS issues.