Blank Source Name with Source Medium of "Shared Job Posting"

Hello,

We have been receiving candidates on a daily basis with a blank Source Name, and all of the candidates have the same Source Medium: "Shared Job Posting". I have read Doc ID 2407273.1 which gives the following description for Shared Job Posting: "The job shared by AddThis or using the copy link on a career site."

We do have AddThis activated on our external career site, but I have performed numerous tests and have been unable to recreate the issue. Every time I apply to a job, the Source Name is populated correctly. I have a Service Request on this issue, but the analyst also doesn't have any ideas of the cause.