Toyota — 2017 Tacoma blind spot monitoring system

Driving down the highway an alert came up on my display: "blind spot monitor not available". Took the truck into the dealer in Reno, NV. They said the system needed to be re-calibrated to the tune of some $800.00. I purchased the maintenance contract for this vehicle just as I did for my 2003 Tacoma. They said the rear bumper was ever so slightly misaligned (parking lot bump?) so the issue was due to "external cause" and therefore not covered with the warranty. I checked and did find that it might be 1/16" closer to the body, but not much. This TRD model is supposed to be able to go off road, in all types of hostile environments bouncing up and down like crazy. I have a hard time believing that a parking lot bump would invalidate the extended warranty. I think Toyota should step up to the plate and re-calibrate the monitor.