Disable Canon 6D WiFi to Tether CamRanger

Wireless tethering is critical to our Architectural photography workflow. However on a recent photoshoot I needed to use a backup 6D instead of the usual 5D and was surprised when CamRanger refused to tether with it. From what I've experienced with CamRanger and knockoff (TPLink router hack) they're bulletproof and work with any Canon or Nikon camera. Not on this day of course... The solution turned out to be super simple but I wasn't able to find it mentioned anywhere online - so I'm posting it here in the hopes that future google'rs will find the answer they need.