I'd like to use the "Offer Slider Thumb" but something is wrong. The blu arrow for the selected (active) item is missing. Inspeting the html, I noticed that a :before element is missing.
This is the blu arrow I'm talking about:
The following image shows the demo on your page. Please note the :before with the blu arrow.
And this is the code in my website. The :before is missing, and I don't have the "blu arrow" of the active item.
It seems related to the slick carousel you're using for the slider thumb, but I couldn't figure out how to solve it.