This happens because the view has already a Contextual Filter in use that is filtering the query from the path arguments. That means that the exposed filter is adding a filter after the main filter from the path.
First of all, enable the "Show the SQL query" option on your views settings (admin/structure/views/settings). This way you will be able to see immediately what is going on.
Furthermore, you can set the contextual filter for the title for the Page views as
- "WHEN THE FILTER VALUE IS NOT IN THE URL -> Display all results for the specified field" because by default it shows titles beginning with letter "a" in the first load.
So to achieve this you should remove any path argument that exists in the path due to the contextual filter (eg for the domain.com/l?title="some title here" you must have domain.com/?title="some title here", without the "l").
You could do this with the following methods:
- Override Views Contextual Filter in View Exposed Form Validation
- Redirect the page removing the last path argument, eg with Rules module or a drupal function
- Use the fresh filter_harmonizer module!
And the winner is probably the filter_harmonizer module.