RelatesTo field conveys the messageID of the related deferred request message. CONNECT does not perform any validation on the incoming deferred response and hence there should be no validation on relatesTo field on Audit Search.
Remove validation for relatesTo field on Audit Search
Trim the input search string as well.
Verify there is no validation for relatesTo field on Audit Search
Verify Audit search to make sure no existing functionality is broken