When using breakdowns that involve custom links, some variables can return without data. Adjusting your implementation can help remedy line items falling under 'none'.
Props and eVars are not included in custom variables by default. However, by changing the value of the linkInternalFilters variable in your implementation, they can be included.
During hit processing, the page name and page URL variable are stripped from all custom link image requests. This processing logic occurs in order to correctly calculate page views. The number of hits where page name / page URL are present determines total page views. Page views do not include custom links.
If you would like to breakdown custom links by page name or the opposite way, pass page name and/or page URL into a custom variable. Include the destination prop/eVar in the linkInternalFilters variable.