Under Windows 10 the screensaver functions only on the primary monitor. Looking for software that can deploy screensaver images (from photos directory) to both primary and secondary monitors.
Try installing picasa from google. Its an obsolete photo editing software that comes with a mighty photo screensaver. You can select folders from your computer and even rss-feeds. the photos will then be displayed on both monitors. works fine for me ;-)
Link to a german download website: http://www.chip.de/downloads/Picasa_13013772.html