Thunderbolt 3 dock disconnects when MacBook sleeps I'm using a CalDigit TS3 Thunder Station 3 dock. When my MacBook sleeps, and I try to wake it using the attached USB keyboard, the DisplayPort connected screen comes on, but the dock looses connection to the USB keyboard, all other USB peripherals. Also, I have a Sonnet Echo Express III-D connected to the Thunderbolt through port on the dock and it also gets disconnected.

The ports won't come back unless I disconnect the dock and reconnect it or restart the computer.

I have contacted CalDigit support and they said:


  The “put hard disks to sleep when possible” energy saver option
  basically sends a “dead” signal to the TS3 when it sleeps as a poor
  attempt to save battery (despite the TS3’s charging abilities). Since
  the computer has manually initiated a shutoff, the TS3 is unable to
  reconnect without a manual reboot- namely, your unplugging and
  re-plugging of the cord.
  
  At the present, we do not know of any plans on Apple’s part to update
  their Energy Saver preferences to reflect the fact that our dock is an
  approved charging source.


This did not solve the problem. Anytime the MacBook sleeps, the TB3 dock stops working and I have to reboot.

Assuming CalDigit is correct in stating there is nothing they can do to cure this behavior, has anyone else been able to find a work-around for this or other TB3 docks?

At present, I assume my only "fix" is to never allow my MacBook to sleep. However, there doesn't appear to be a way to prevent macOS High Sierra from sleeping. Even with utilities like Amphetamine, the computer still sleeps but is woken immediately by the utility, causing the dock to disconnect.
Given that the computer sleep seems to be the problem, I turned off the "Power Nap", and it seems to be working for me now.


System Preferences > Energy Saver
Power Adapter tab
Uncheck "Enable Power Nap while plugged into a power adapter


This seems to be preventing the computer from sleeping and my external monitor has been fine. Note that I still turn off the display after 10 minutes, so I don't think this is harmful to the computer.

Of course, this setup is only when plugged in, which is the only time I care about the external monitor.