Question Title Validation Happens Twice in Authoring Page

[noce2]

The question authoring page uses a custom asynchronous validator to check whether question title already exists when a user typs one into the form. The validation is supposed to happen only once for each typed value. It currently runs twice. Once when the question title is typed into its input and again when the submit event is fired. This can be observed by placing a breakpoint in the onSubmit method of the question-authoring-page.component.ts and in the operator within the validator itself.

This validation should only occur once so the purpose of this bug ticket is to fix that.

• The asynchronous custom validator for question titles runs only once, rather than again when the submit event is fired.

A reference app here seem not to have the same issue.