How can I show a view in panel with argument in drupal 7
In order to use "contextual filters" for a view within a panel, you need to change the style of the panel. It seems that even though they are called contextual filters, they expect an argument. Make sure you have the view panes enabled in modules and create the same view with the style of view pane. You will then get an additional menu called "pane settings". One of the settings is "argument input", select "from context" and the required context, and it should work fine. This was something I was really stuck on till  found this solution.

also, if you are trying to pass a taxonomy term, you have to make sure it is formatted correctly to use in the filter. See this post for details

Views contextual filters taxonomy name