The "upgrade" form 16.10 to 17.04 has been very rocky for my system. The big issue I'm currently dealing with involves power settings that I believe were working perfectly prior to the upgrade.
I first noticed this issue yesterday when I walked away from laptop for a period of 15-20 minutes. Upon returning to my laptop, I found that my screen was still on and that my session was not locked. This is both a battery life issue, as the screen is a major power consumer, and a security issue, for obvious reasons.
I confirmed that my settings had "Dim screen when inactive" enabled and that "Blank screen" was set to 15 minutes. I then spent the next 30 minutes playing with my settings, including toggling certain settings and setting the "Blank screen" to 1 minute to quickly test things.
Unfortunately, nothing worked. My battery was pretty low at the time, so I plugged in my power cord. Suddenly, everything was working properly again! This was both good news and bad news. The good news was that the features were still present. However, the behavior is counter-intuitive. From a security standpoint, the benefit of screen locking is arguably equally valuable whether on battery power or plugged in. However, from a power consumption standpoint, there is no question that the dim screen/blank screen feature is incredibly more useful when on battery power!
So my question is, does anyone know how I can fix this issue? I would settle for simply having the behavior reversed. That is, the dim screen/blank screen feature working when on battery, but not working when plugged in; ideally, it would work regardless.