Cannot get return from golang temporal update hander

I am following the example from https://github.com/temporalio/samples-go/tree/message-passing/message-passing-intro. I found that the script would block in first

err = updateHandle.Get(context.Background(), &previousLang)

from /starter/main.go.

It will not return error or result from the update handler and the workflow is keep running

Expected:
The script would complete and the workflow is completed.

Additional Infomation:

I am using

temporal server start-dev \ --dynamic-config-value frontend.enableUpdateWorkflowExecution=true \ --dynamic-config-value frontend.enableUpdateWorkflowExecutionAsyncAccepted=true

to start a temporal server.