This behavior is strange for me too.

NO. Displays still goes black after several minutes as i said before.

haven't got, what do you mean?

I got the same

185726

Didn't find any power management software.

Of course it's not hit the set up time. It turns off much more earlier. I tried to set up different time and test. I got the same.
I have a laptop and an additional monitor. Monitor always black...

Hi all! My computer always turns display off when i lock it. Not immediately, of course, but within 5-10 minutes it happens.
I tried to set up more time via Console lock display off timeout option....