This is what I got in the Debug logs:
02/28/2021-15:37:18.386 [Erro] ExceptionMessage : (Operation timed out. (Exception from HRESULT: 0x80131505)), ExceptionToString: (System.Runtime.InteropServices.COMException (0x80131505): Operation timed out. (Exception from HRESULT: 0x80131505)
at Microsoft.StorageMigration.Service.DeviceInventoryTask.GetDevice()
at Microsoft.StorageMigration.Service.StorageMigrationService.CompleteDeviceInventoryTask(String jobName, Guid taskId)
at SyncInvokeCompleteDeviceInventoryTask(Object , Object[] , Object[] )
at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage11(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)) [d:\os\src\base\dms\service\ErrorHandlerBehaviorAttribute.cs::HandleError::37]