pearly theme customisation

We've been trying to do a few bits using the pearl theme which seems should be easy, but dont seem to be working.

1) we want to add more sliders to the home page, it currently has:
{{widget type="WeltPixel\OwlCarouselSlider\Block\Slider\Products" products_type="new_products"}} for new products, I have tried:

{{widget type="WeltPixel\OwlCarouselSlider\Block\Slider\Products" products_type="sale_products"}}

&

{{widget type="WeltPixel\OwlCarouselSlider\Block\Slider\Products" products_type="bestsell_products"}}

none of these show anything (i do have items on sale and orders places)

can someone confirm the names to use for the widgets or advise me what i'm doing wrong?

2) When I re-order my categories in the catalog screen (drag & drop) and save them it doesn't save and messes them up again, they were ordered previously before the theme install.

3) We are wanting to change the style of the drop down boxes - can this be done?