Thanks. I'll keep trying. I've cleared all browsing data in Chrome and rebooted the laptop, but no luck. It's working on my phone. I'll try another browser.
I thought I'd update this thread, in case anyone else runs into this problem. After all the things I tried above, I started to work through the Chrome Extensions, turning them off one-by-one, with the most obvious ones first. I hit gold on the second one, DuckDuckGo Privacy Essentials. I have now disabled this extension for the BFC main site, and now the iFollow functionality works. I also clicked on the link and reported the site as having an issue.