External display connected via USB-C > VGA goes to endless sleep/wake loop I have a dell external display connected to my mb pro 2017 (Mojave), but whenever i try to sleep my mac (with sleep command), it goes to endless loop trying to sleep and then immediately wakes up, because external display won't sleep.

Is there any workarounds / apps to prevent this behavior?
I just had to put the mac in to sleep using external display. Also closing the LID won't work, you have to sleep the external display first, then you can close the LID.