Every time a constituent uses a specific link to Luminate Online from a non-Luminate Online page, they lose some of their session data.
This usually happens when the link on the non-Luminate Online page is a secure link. For example, you may have placed a link to your eCommerce store as a part of a Google ad and when someone donates using that link, the session loses the source data. Another example might be that you have placed a link to a donation form in Luminate CMS and when someone donates using that link, the session loses the subsource data. In this case, it is important to go check the HTML of the link on the non-Luminate Online page. If that link is secure, that is likely your problem. Find the non-secure link in Luminate Online and replaced the secure link with that non-secure link. This will keep the session data from being lost. For intermittent issues, review this article.