the search tab "change assignment" does not work

Summary:

hello,
I have a problem with the search tab” change assignment”
the search does not work.(I attach a screenshot)
I am with an administrator user
Thank you

Thanks
Gianfranco

Content (please ensure you mask any confidential information):

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

Code Snippet (add any code snippets that support your topic, if applicable):