[Theme: Virtue] Mobile version of site no longer loading

My website is https://www.lrfoodcast.com.

Within the past few weeks, my website started loading as the full site on mobile devices instead of the mobile friendly site. The menu was once tucked away in a drop-down, now it takes up most of the screen upon loading. Likewise, the pictures used to scale to the phone size, but while the text still scales, the pictures display in desktop mode, creating a relatively thin line of text broken by massive pictures. It was working just fine until earlier this month, and I’m not sure whether the upgrade to 4.0 or a theme upgrade is responsible. Regardless, I can’t find a setting to put everything back to normal. Can you help?