Pinboard Portfolio

I am using Pinboard Theme by One Designs. I have set up a “portfolio” page by creating a page with the “Portfolio” template, creating a “Portfolio” category, assigning multiple posts to that category. For some time this worked just fine; but now my “Portfolio” page just links right back to my home page. No idea why. Please advise.
Site is https://www.xbydesign.biz.