Homepage Slider cutting off top?

Look like your thumbnails are cropped. Your original image size is larger than slider thumbnail size and crop mode is enabled for thumbnail settings so its cropped to fit the area.

Try using crop mode false or resize your images according to your needed slider width, height by yourself using Photoshop or other image editor and upload again as featured thumbnail. Then go to adv. slider ‘Container & Thumbnail’ section and select ‘full’ for ‘Select Thumbnail’ drop down.