为什么我的TFS构建标签在10次构建后从全局列表中消失了？为什么他们在标签上有一个斜线？

My build retention policy deletes Details, Drop Folder, and Symbols only, after 20 successful builds. However, my Global List with build labels is only retaining the last 10 builds. All builds were being retained in the global list before my recent upgrade from TFS 2010 to TFS 2013.My build retention policy deletes Details, Drop