This probably may not have to do with Nintex but maybe you can addvise.
I am running SharePoint 2016 on-premise and Nintex 2016.
I am able to view the list and see all the entries which is round 200 items.
However, when using the search field in a sharepoint list, it throws an XML error:
Error: Invalid XML: 10095528EKE4000EKEAIW 13327Error: Invalid XML: 10096803EKE3000EKEAdient DE 1694210095529EKE3000EKEAdient DE 16942