When generating the code with Nswag, the following codes are disabled at the beginning but are not restored at the end when all the other codes are restored. Therefore, this needed to be adjusted manually, but it is easy to overlook.

#pragma warning disable 649 // Disable "CS0649 Field is never assigned to, and will always have its default value null"
#pragma warning disable 8765 // Disable "CS8765 Nullability of type of parameter doesn't match overridden member (possibly because of nullability attributes)."