Add wait allows enough time for alert creation

What does this MR do and why?

Describe in detail what your merge request does and why.

Add some wait logics to allow enough time for new alerts to be created and displayed on index page.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #390794 (closed)