Hi Kevin,
The symptoms you describe sound like a connector issue. Since the connection to the motherboard is halfway up the side of the phone, I'd say it's the other end that's having problems. Unfortunately, the connections to the glass itself are pretty much non-repairable, so chances are you're looking at needing to replace the screen again.
The good news here is that iFixit screens have a lifetime warranty and a failure that's not due to physical damage should be covered. My suggestion would be to go ahead and contact the iFixit Store personnel and let them know what's going on. Assuming they agree it should be covered, they'll send you a brand new replacement kit the same as your original purchase. Best way I know of contacting them is via email at support@ifixit.com.