On my local machine, the hideBanner() function doesn't work in mobile because it throws the following JS error:
$.toJSON is not a function
in BannerController:
$.cookie(
'centralnotice_hide_' + mw.centralNotice.data.category, $.toJSON( cookieVal ), { expires: d, path: '/' }
);
I'm not sure why $.toJSON isn't working on mobile, but it's deprecated anyway and is going to be removed from core in MW 1.25. You should use JSON.stringify instead.
Version: unspecified
Severity: major