FlatPlus layout not working on iPhone

Cannot for the life of me figure out why I can't get the FlatPlus layout to work on Phone.
It works great when I'm on a desktop and even when I collapse the screen into responsive mode. But when I open it on my iPhone it goes to the old layout / design?

http://www.gigharborchamber.net/home-sp-275/community-calendar/month.calendar/2017/01/12/-

I have JEvents on other sites and it's working great.