Slider problem in Wordpress website

We hired a freelancer to do web speed optimisation, after he installed couple of plugins, our homepage section have problem with sliding especially in iPhone models. Our in house programmer tried to rectify the issues but couldn't resolve it. Please try to find the website URL from the video or request from me as we should not reveal the client's website here.

Few sections were affected :
1. homepage slider
2. homepage product list tab slider
3. homepage blog section slider
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