NHTSA Complaint #11426489 — 2019 CHEVROLET TRAVERSE

My 2019 Chevy Traverse was purchased new in August of 2018. It has approx 34,500 miles on it as of 7/26/21. Tire size: 255/55 R 20 107H. The vehicle has been in for regular maintenance/service at the original dealership since it was purchased. Around March 2021, I noticed the outside tread on all 4 tires becoming brittle and breaking off. There are small chunks of the tread missing and some type of thread showing where the chunks have come off. I went to my local Costco and the associate in the tire department told me that I should not be driving on it because the tires could blow. I wanted a second opinion and went to my local Discount Tire. The associate told me that what was happening was called "chunking" and it was not common (actually rare to happen) and I should call Continental Tire. No alarms/warning lamps have gone off due to this issue.