I have come to my wit’s end having to make so many changes repeatedly because of these issues, plugin compatibilities, and stuff.
I hope this hassle will stop someday and I can use the theme without trouble?
I hope you are well today and thank you for your question.
I have tested it on my test site using Yellowpencil editor & WPBakery editor and it’s working fine for me using the latest version of the Gillion theme.
Please make sure that you are using the latest version of the theme and plugins.
The slider displays fine for me on mobile as shown in the attached screenshot.