"Warning, entry sensor open" but devices all show as closed

This is quite annoying. Base station keeps saying "Warning, entry sensor open," but my list of devices shows all of them closed. Updating makes no difference. This has happened before, and I have to run around the house trying one after another, turning the alarm on and off etc. Right now I'm leaving it off until I can figure out a better way. Anybody have any suggestions? Many thanks.