Question:

Why were my Always On Display (AOD) clock settings reset after updating my device's operating system to Android 11?

Answer:

As part of the new version of Android, some changes were made to simplify the available clock styles for the Always On Display feature. This involved removing clock styles that were not frequently used. If your chosen clock style had low usage and was removed during this process, your AOD clock settings would have reverted back to the default option after updating to Android 11.