Screensaver stopped working, High Sierra

I have an older MacBook Pro (mid 2010), with High Sierra version 10.13.6. As far as I know the screensaver was working before I installed Fliqlo clock screensaver. I tried the new and old version and they didn’t work (they worked in preview mode though). I uninstalled them and then realized none of my screensavers were working when I tried to pick another stock screensaver. The preview works, but not when it actually goes to sleep. The screen is just black. I’ve checked the sleep timing in energy saver, I’ve restarted with new screensaver and after uninstalling. I’m not really sure what’s wrong.