Samsung SH850 / 2017 MBP Sleep Issues

I have a 2017 non-touchbar MBP with a Samsung SH850 USB-C monitor I just purchased. Everything works great when the computer is on and I'm using it. However when I put it to sleep, the monitor tries to go to sleep after a few seconds, and then I hear the "blonk" sound on the computer as if I had just plugged in the power, and the screen comes on black for a second, then goes back off. Then the process repeats itself, every minute or so.

This also seems to disconnect the USB hard disks I have connected to the monitor's USB hub, as when I wake the system from sleep I see a ton of "Drive not disconnected / ejected properly' notifications on the right.

I also tried shutting down, and the monitor seemed to turn the computer back on all by itself!

So last night I tested this with the lid opened, and noticed that the laptop screen says "100% Charged" when this occurs.

Did a clean install of MacOS High Sierra. The issue persists. One thing I noticed last night is the issue only occurs when I tell the system to go to sleep via the Apple menu. If it enters sleep via the sleep timer, the issue does not occur.