Select a Coworker as a Contact does not return any person and times out

Summary:

When trying to add a contact who is an existing employee in My Client Groups > Family and Emergency Contacts > Add > Select a Coworker as a Contact, the search does not yield to any result.

Content (please ensure you mask any confidential information):

When searching for name (not exact, first name for example), it just keeps on loading until eventually it times out . It seems like it lots of users (>500) that start with TA_Robot_Rest affects the performance on this page.

Can you confirm if this search should not have any limitation?

Version (include the version you are using, if applicable):