PDF's open slowly from "server"

I have a workstation I use (Windows 7 Pro) as a server that I keep files on. When other computers (Windows 7 Pro) access PDFs located on this "server" they take about 90-120 seconds to open. This just started happening recently. As far as I can tell it is only PDFs and only on Adobe Acrobat Reader DC. They open fine in Chrome and using Foxit Reader. I have tried changing the security settings in Acrobat, as well as disabling all plugins. Any advice on troubleshooting would be appreciated.