EntityFramework Core different queries between environments

I'm running a very simple database entity update using EntityFrameworkCore.SqlServer v 5.0.2 but I'm getting a weird behavior... On my local environment the update query is working just fine, but when I switch the environment to Production I get an exception.

I debugged further and realized that in production EntityFramework is trying to insert a record in a different table using the same primary key ID which is resulting in the exception.

Here's my code snippet:

var package = await _context.Packages.FindAsync(request.Id);
if (package == null) throw new RestException(HttpStatusCode.NotFound, new { package = "Could not find Package" });

package.Name = request.Name ?? package.Name;
package.ValidUntil = request.ValidUntil ?? package.ValidUntil;
package.Variants = request.Variants ?? package.Variants;
package.Active = request.Active ?? package.Active;

var success = await _context.SaveChangesAsync() > 0;

Some notes: Variants is an entity that includes an Enum called CurrencyId. I have a database table the keeps the values of those enums as records in the Db

public class Variant
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    public SubscriptionTypeEnum SubscriptionTypeId { get; set; }
    public virtual SubscriptionType SubscriptionType { get; set; }
    [Column(TypeName = "decimal(18,2)")]
    public decimal VariantPrice { get; set; }
    public CurrencyEnum CurrencyId { get; set; }
    public virtual Currency Currency { get; set; }
}

and the exception that is thrown (only in production) is the following

Microsoft.Data.SqlClient.SqlException (0x80131904): Violation of PRIMARY KEY constraint 'PK_Currencies'. Cannot insert duplicate key in object 'dbo.Currencies'. The duplicate key value is (0).
The statement has been terminated.
   at Microsoft.Data.SqlClient.SqlCommand.<>c.<ExecuteDbDataReaderAsync>b__169_0(Task`1 result)
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
   at System.Threading.Tasks.Task.<>c.<.cctor>b__277_0(Object obj)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location ---
   at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
ClientConnectionId:a1e3bf81-e486-4e22-9ce6-e0b6601d4bd1
Error Number:2627,State:1,Class:14

Again to re-iterate this is only happening in production but locally the update is working fine.

In clue what might be the issue and how to fix it?