This article says Tesla is building their own chips to solve the chip shortage. As far as I know, Tesla has never built the microcontrollers that are causing the chip shortage. Tesla designs its own very high performance graphics processors that take the place of Nvidia chips. These have nothing to do with the microcontrollers that are used in the mundane tasks like sensor controls for rolling up the windows. The shortages affect these microcontrollers.
https://electrek.co/2022/01/07/geely-and-foxconn-establish-jv-to-push-back-against-chip-shortage/