New Child Theme

Hi All,
I changed from a non responsive to responsive a while ago before reading some of the warnings.
I have managed to get most of it working but finally found the time to sort those little issues.

I want to have a fresh Child theme start and like the look of https://www.premiumpress.com/childthemes/?oldtheme=crown/

However the theme doesn’t seem to be consistent. The home page looks different between Firefox and Chrome and seems to jump between two different looks. With the issues I’ve had with the theme I have been using: https://www.premiumpress.com/childthemes/?oldtheme=business-directory/ made more difficult by domain mapping issues etc as we have a multisite install, I don’t want to change to a new Child theme that may have issues in it.

Could someone just confirm if this “Crown” child theme is working as intended or if it has issues before I download it?

Thanks for any help.