Known Issue: POS and POCO Shields (http://community.eveonline.com/news/news-channels/eve-online-news/parallax-known-issue-with-pos-and-poco/)
6 November 2015, 2:49 pm
Hello Players
In some instances, Customs Offices and Player Owned Starbases can exit reinforcement with more than 25% shield, causing them to enter reinforcement again once attacked. We are working on a solution to this problem and hope to resolve it early next week.
Source: EVE Online News