I'm looking for an easy way to set a global configuration in my DbContext to store as string any nullable or non-nullable Enumerations.

I've already tried with this:

configurationBuilder.Properties<Enum>().HaveConversion<string>();

Unfortunately if the Enum is defined as Enum? the code above throws the following:

System.NullReferenceException: 'Object reference not set to an instance of an object.'
at MongoDB.EntityFrameworkCore.Serializers.ValueConverterSerializer`2.MongoDB.Bson.Serialization.IBsonSerializer.Serialize(BsonSerializationContext context, BsonSerializationArgs args, Object value)
at MongoDB.Bson.Serialization.IBsonSerializerExtensions.Serialize(IBsonSerializer serializer, BsonSerializationContext context, Object value)
at MongoDB.EntityFrameworkCore.Storage.MongoUpdate.WriteNonKeyProperties(IBsonWriter writer, IUpdateEntry entry, Func`2 propertyFilter)
at MongoDB.EntityFrameworkCore.Storage.MongoUpdate.WriteEntity(IBsonWriter writer, IUpdateEntry entry, Func`2 propertyFilter)
at MongoDB.EntityFrameworkCore.Storage.MongoUpdate.ConvertAdded(IUpdateEntry entry)
at MongoDB.EntityFrameworkCore.Storage.MongoUpdate.Create(IUpdateEntry entry)
at System.Linq.Enumerable.SelectEnumerableIterator`2.MoveNext()
at System.Linq.Enumerable.<OfTypeIterator>d__66`1.MoveNext()
at MongoDB.EntityFrameworkCore.Storage.MongoUpdateBatch.<CreateBatches>d__7.MoveNext()
at MongoDB.EntityFrameworkCore.Storage.MongoClientWrapper.<SaveUpdatesAsync>d__10.MoveNext()
at MongoDB.EntityFrameworkCore.Storage.MongoDatabaseWrapper.<SaveChangesAsync>d__3.MoveNext()
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.<SaveChangesAsync>d__111.MoveNext()
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.<SaveChangesAsync>d__115.MoveNext()
at Microsoft.EntityFrameworkCore.DbContext.<SaveChangesAsync>d__63.MoveNext()
at Microsoft.EntityFrameworkCore.DbContext.<SaveChangesAsync>d__63.MoveNext()
at Program.<<Main>$>d__0.MoveNext() in C:\Repos\CustomersApp\Program.cs:line 29

Code used to reproduce the issue attached.

EF Core version: Microsoft.EntityFrameworkCore 8.0.6
Database provider: MongoDB.EntityFrameworkCore 8.0.3
MongoDB: MongoDb.Driver 2.27.0
Target framework: .NET 8
Operating system: Visual Studio 2022 17.10.4