mojave phot screensaver control

I have had a photo slideshow set as my screen saver for a long time. The most recent update required me to reselect it a my screen saver. Previously, I could use the left and right arrow keys to go forward and backward in the slide show without waking the computer--a useful feature as in screensaver mode my computer served for a time as a digital frame. That function seems to be lost in the latest update. Any suggestions? Did I miss something when I re-selected photos as my screensaver?