The ATF Warmer failed. This allowed engine coolant and transmission fluid to mix. This caused the engine and transmission to overheat. No warning messages appeared up until the transmission overheated. A warning appeared about the transmission, but not about the engine. Honda says that they do not think my VIN was impacted by this known issue. And, yet, my car has a textbook defective ATF warmer with 100% overlap in symptoms with a known service bulletin issue (17-035 from April 7, 2018).