EF 7 + Oracle DB - InvalidCastException: Specified cast is not valid - oracle

Question

I am trying to query an Oracle database from .NET7.
I used database first approach to generate my model context. When querying, I get the following exception:
InvalidCastException: Specified cast is not valid.
Oracle.ManagedDataAccess.Client.OracleDataReader.GetInt16(int i)...
That's my (truncated) object class, and the property causing the exception (when I comment the property, select query is working):
public partial class Car
{
public string? Owner { get; set; }
[...]
}
Database looks like this:
CREATE TABLE "Car"
( "Owner" VARCHAR2(6 BYTE)
[...]
Generated context:
modelBuilder.Entity<Car>(entity =>
{
entity.Property(e => e.Owner)
.HasMaxLength(6)
.IsUnicode(false)
.HasColumnName("Owner")
[...]
}
Packages:
Oracle.EntityFrameworkCore 7.21.8
Microsoft.EntityFrameworkCore.Design 7.0.1
What's the problem? Is it because the column is nullable? I have no idea.
EDIT:
Seems like the problem is the stored data. Some rows must be corrupted / not like the column definition.
EDIT2:
That's the LINQ query:
return await _context.Cars.Take(10).ToListAsync();
Stacktrace:
System.InvalidCastException: Specified cast is not valid.
at Oracle.ManagedDataAccess.Client.OracleDataReader.GetInt16(Int32 i)
at lambda_method19(Closure, QueryContext, DbDataReader, ResultContext, SingleQueryResultCoordinator)
at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.MoveNextAsync()
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
at CarService.Controllers.CarController.GetCars(Int32 plate) in C:\GIT\webservices\car-service-dotnet\CarService\Controllers\CarController.cs:line 45
at lambda_method5(Closure, Object)
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)