Hello, Karawhereibelong,
Image size > Cover option affects desktop and mobile. There is no option to set it up separately.
We’ve added the custom CSS code – https://prnt.sc/NAcLQbQqABS9 , the result is – https://prnt.sc/4O_ZV_d4pTy2
If you are not satisfied with the look of our slider element, we recommend that you use the Slider Revolution plugin instead, as per the instructions in its documentation.
Kind Regards,
8theme team