Upgrading from 7.5.x to 8.0.x results in runtime error

[alberk8]

I am encountering the error below after upgrading Microsoft.AspnetCore.OData from version 7.5.x to 8.0.x. The application was working correctly with OData prior to the upgrade.

How to I get the detail of the 'PublicKey[Nullable=False]' of type 'Edm.String' has a null value,?

[17:20:13.043  ERR][0HMI586FBK71I:00000012] Microsoft.AspNetCore.Server.Kestrel: Connection id "0HMI586FBK71I", Request id "0HMI586FBK71I:00000012": An unhandled exception was thrown by the application.
Microsoft.OData.ODataException: The property 'PublicKey[Nullable=False]' of type 'Edm.String' has a null value, which is not allowed.
   at Microsoft.OData.WriterValidationUtils.ValidateNullPropertyValue(IEdmTypeReference expectedPropertyTypeReference, String propertyName, IEdmModel model)
   at Microsoft.OData.WriterValidator.ValidateNullPropertyValue(IEdmTypeReference expectedPropertyTypeReference, String propertyName, Boolean isTopLevel, IEdmModel model)
   at Microsoft.OData.JsonLight.ODataJsonLightPropertySerializer.WriteNullPropertyAsync(ODataPropertyInfo property)
   at Microsoft.OData.JsonLight.ODataJsonLightPropertySerializer.WritePropertyAsync(ODataProperty property, IEdmStructuredType owningType, Boolean isTopLevel, IDuplicatePropertyNameChecker duplicatePropertyNameChecker, ODataResourceMetadataBuilder metadataBuilder)
   at Microsoft.OData.JsonLight.ODataJsonLightPropertySerializer.WritePropertiesAsync(IEdmStructuredType owningType, IEnumerable`1 properties, Boolean isComplexValue, IDuplicatePropertyNameChecker duplicatePropertyNameChecker, ODataResourceMetadataBuilder metadataBuilder)
   at Microsoft.OData.JsonLight.ODataJsonLightWriter.StartResourceAsync(ODataResource resource)
   at Microsoft.OData.ODataWriterCore.<>c.<<WriteStartResourceImplementationAsync>b__196_0>d.MoveNext()

[alberk8]

Additional Info. The Poco class Student is retrieved from a MongoDB. When I inspect the retrieved data from MongoDB the Remarks is set to null as there is no error in that but why is it complaining on PublicKey on a complex Type when there is no key defined. This works perfectly in AspnetCore Odata version 7.5

VS 2022
<nullable>enabled</nullable>

public class Grade 
{
   public string Subject {get;set;}="";
   public string Remarks {get;set;} ="";
   public int Score {get;set;}
}

public class Student
{
   [Key]
   public Guid ID {get;set;}
   public String Name {get;set;} = "";
   public Grade Grade {get;set;}
}

<ComplexTypeName="Grade">
<PropertyName="Subject" Type="Edm.String" Nullable="false"/>
<PropertyName="Remarks" Type="Edm.String "Nullable="false"/>
<PropertyName="Score" Type="Edm.Int32" Nullable="false"/>
</ComplexType>

<EntityTypeName="Student">
<Key>
<PropertyRefName="ID"/>
</Key>
<PropertyName="ID"Type="Edm.Guid" Nullable="false"/>
<PropertyName="Name" Type="Edm.String" Nullable="false"/>
<PropertyName="Grade" Type="MyEDM.Grade" Nullable="false"/>
</EntityType>