Based on the given description, I understand that you have AAM implemented on the page and using which you are able to see one event call along with some set of parameters. Also, with VisitorProfileViewer you are able to see trait getting qualified.
But I am not clear when you say "but still we can,t see the Trait key in AAM and its value". Please help me in understanding the issue.
If you are seeing trait under VisitorProfileViewer then you wont see that key-value pair in unused signal report.