What is one of the first troubleshooting steps to try if Face ID is not working after an update?

Resetting Face ID is an effective first troubleshooting step when encountering issues after an update because it allows the system to reinitialize the biometric data used for Face ID. Updates can change various system files and settings, which might disrupt the previous configuration of Face ID. By resetting it, you prompt the device to recalibrate and set up the facial recognition system anew.

Checking that nothing is covering the TrueDepth camera is also a crucial step if Face ID fails, but it’s typically wise to rule out software issues first, especially after an update. Adding an alternate appearance could be useful if the primary facial recognition fails, but that step comes after ensuring the system is functioning properly again. Restarting the device is a general troubleshooting step that can resolve many issues, but resetting Face ID directly targets the problem you're experiencing with facial recognition. Therefore, initiating the process to reset Face ID specifically addresses potential issues created by the update.