You are having issues finding a specific sender's or recipient's email using the search field of the quarantine portal.
You may have copied the sender's or recipient's ID field with spaces or the browser's cache was still generating the same result while searching.
Symantec recommends typing the Email ID rather than copy/paste as this operation may include a different character's format.
Additionally, clearing the browser's cache or using an in-private mode of the browser would help in resolving this issue.
If the same issue still persist, then please report it to your support team.