✅ .NET 8 enum to string serialization throws an exception

c#
public sealed record GetLinkMetricsRequest
{
    [FromRoute]
    public string Id { get; set; }
    
    [FromQuery]
    public TimePeriodUnit? TimeUnit { get; set; } = TimePeriodUnit.Day;
    
    [FromQuery]
    public int? Units { get; set; }
}

[JsonSourceGenerationOptions(UseStringEnumConverter = true)]
[JsonSerializable(typeof(GetLinkMetricsRequest))]
public partial class TimePeriodUnitJsonContext : JsonSerializerContext;


// applied to the Controllers
var options = new JsonSerializerOptions
{
    TypeInfoResolver = JsonTypeInfoResolver.Combine(ContextA.Default, ContextB.Default, ContextC.Default);
};

c#
public sealed record GetLinkMetricsRequest
{
    [FromRoute]
    public string Id { get; set; }
    
    [FromQuery]
    public TimePeriodUnit? TimeUnit { get; set; } = TimePeriodUnit.Day;
    
    [FromQuery]
    public int? Units { get; set; }
}

[JsonSourceGenerationOptions(UseStringEnumConverter = true)]
[JsonSerializable(typeof(GetLinkMetricsRequest))]
public partial class TimePeriodUnitJsonContext : JsonSerializerContext;


// applied to the Controllers
var options = new JsonSerializerOptions
{
    TypeInfoResolver = JsonTypeInfoResolver.Combine(ContextA.Default, ContextB.Default, ContextC.Default);
};

An unexpected error occurred. See the inner exception for details. System.NotSupportedException: JsonTypeInfo metadata for type 'AnalyticsService.Api..' was not provided by TypeInfoResolver of type 'System.Text.Json.Serialization.Metadata.JsonTypeInfoResolverWithAddedModifiers'. If using source generation, ensure that all root types passed to the serializer have been annotated with 'JsonSerializableAttribute', along with any types that might be serialized polymorphically.

An unexpected error occurred. See the inner exception for details. System.NotSupportedException: JsonTypeInfo metadata for type 'AnalyticsService.Api..' was not provided by TypeInfoResolver of type 'System.Text.Json.Serialization.Metadata.JsonTypeInfoResolverWithAddedModifiers'. If using source generation, ensure that all root types passed to the serializer have been annotated with 'JsonSerializableAttribute', along with any types that might be serialized polymorphically.