If the power-saving settings don't do the trick, You may want to try a reset of the device.
As annoying as it might sound, resetting the device after any big updates seems to address many issues that crop up (definately not all, but ones similar to the one you posted are often resolved).
Just remember to backup any valuable data PRIOR to performing a reset.
Directions can be found here:
Or if that doesn't work, you can force the process as documented here: