Turns out my problem is more complicated than I thought. Resetting everything for my home hardware didn't fix it. I don't think its a DNS issue since nslookup on bisonville.com returns the same IP on my home PC that doesn't work and on my mobile device which does work when on AT&T's network.

Anyone else who uses Midco in south Fargo having issues??? Tracert shows a timeout on the hop from he.net (Hurricane Electric - who I believe runs Midco's internet backbone) and Bisonville's IP. I'll check with Midco support but I'm guessing I'm seeing an ISP level routing issue so others are running into the same.