Errore di connessione su UserManager CreateAsync

Sto ottenendo il seguente errore quando provo a creare un nuovo utente usando il metodo CreateAsync di UserManager. Sto usando IdentityUser non modificato e IdentityRole. Ho alcuni DBSet che popolano i dati del database, quindi leggere non è un problema, sembra proprio esserci una scrittura.

    {System.InvalidOperationException: Connection must be valid and open to commit transaction at MySql.Data.MySqlClient.MySqlTransaction.Commit()
   at Microsoft.EntityFrameworkCore.Storage.RelationalTransaction.Commit()
   at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.<ExecuteAsync>d__10.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.<SaveChangesAsync>d__54.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.<SaveChangesAsync>d__52.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.EntityFrameworkCore.DbContext.<SaveChangesAsync>d__35.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Identity.EntityFrameworkCore.UserStore`9.<CreateAsync>d__36.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Identity.UserManager`1.<CreateAsync>d__68.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Identity.UserManager`1.<CreateAsync>d__73.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Controllers.Auth.AuthController.<Register>d__9.MoveNext() in AuthController.cs:line 102}

Sto usando;

• MySQL Entity Framework Core 7.0.7-m61
• Visual Studio 2017
• ASP.NET Core MVC 1.1.0
• Identità 1.1

La riga 102 menzionata nell'errore è var result = attende userManager.CreateAsync (newUser, model.Password);

        [HttpPost]
        public async Task<ActionResult>Register(RegisterViewModel model)
        {
            try
            {
                if (ModelState.IsValid)
                {
                    var newUser = new IdentityUser
                    {
                        Email = model.Email,
                        UserName = model.Username
                    };

                    var result = await _userManager.CreateAsync(newUser, model.Password);

                    if (result.Succeeded)
                    {
                        await _signInManager.SignInAsync(newUser, false);
                        _logger.LogInformation($"New user account created: {model.Username}");

                        return RedirectToAction("Index", "App");
                    }

                    _logger.LogError($"Registration failed for {model.Username}: ", result.Errors);

                    return View(model);
                }

                return View(model);
            }
            catch (Exception ex)
            {
                _logger.LogError("Database Failure: ", ex);
                return View(model);
            }
        }

Sto imparando asp.net e sto inciampando qui su quello che spero sia un errore evidente in quanto sembra essere un problema di connessione di base, ma non ha senso perché il database può essere interrogato usando IdentityDBContext ma non attraverso UserManager, che nella mia comprensione utilizza la connessione IdentityDBContext.