Slow search when adding additional approver to a requisition (Redwood)

When creating a purchasing requisition, the user has the option to add an additional approver above or below the current participant. In the RSSP version of this, the username search field is very unresponsive, sometimes taking upwards of 30 seconds to present results.

For us, this is to the point where users will think the search is broken and will change it/add more letter which will reset the search.

Is there any known issues relating to this search from other users?