PDF documents opened from NetDocuments from the Chrome browser do not check in automatically when closed. When you close the document in Power PDF, the pdf file is still checked out in Chrome. Restarting or refreshing the browser does not check in the document. We tested with IE and after a restart or refresh the browser document checked in. We then tested with the Adobe Reader and found the same exact issue with the Chrome browser.
This is a known issue with browsers other than IE, and NetDocuments,
Here is a link to an article on this in the NetDocuments knowledgebase: https://support.netdocuments.com/hc/en-us/articles/205218040-NetDocuments-in-Non-ActiveX-Browsers The browser comparison from their site is attached. You can see they are specifically integrated with IE and recommend you use this browser.