my DN screensaver turns on, fwiw. I’ve never timed it though to see after how long and I tend to turn it off if I’m going to leave it alone too long because I have screen burnaphobia.
also, if it weren’t beneficial they wouldn’t have added it to digitakt after the fact, but they did. perhaps check your firmware version? I don’t know. it works and turns on in my case and I’m no one special, should certainly work for you.