I used to have a digital clock as the screensaver, today that option has disappeared and the only options I have are the city scape and logo rain screensavers.
I tried searching and installing "Screensaver" in the channels but the ones I found only added new channels that you had to open to show the screensaver rather than happened automatically when the Roku was inactive.
How do I get my clock back, or something new to use a screensaver under Settings > Theme > Screensaver
I had the same issue. Search “Roku Digital Clock”, download then set as screensaver. (settings, theme, screensaver, Roku digital clock, set as screensaver) It worked for me. Lemme know if it works for you.