I find myself with files displaying orphaned tags when executing certain workflows. Unfortunately they only become visible after I close and reopen the file. So I can never nail down the actual specific workflow. However, the elements are almost always tags for contours. But occasionally, they are DTM feature tags.
My suspect tool is the Update 3D/Plan Surface Display as it is almost always involved in my workflow when this occurs and it did not happen very often before I started using this command.