Can't reboot Mac with Blackmagic eGPU connected

I just got my new 2018 model Macbook Pro (15' 2.2Ghz hex-core i7, Radeon pro 560X, 16GB DDR4 RAM, 512 GB SSD). And a fancy Blackmagic eGPU.

Everything was fine, until I rebooted my Mac. I found that the Mac won't reboot when it was connected to eGPU.

It was like this:

My Mac is connected to eGPU (with lid closed), which is connected to a 4k TV via HDMI cable. When I need to restart the OS I reboot the Mac but instead of rebooting the Mac just shuts itself down.

It doesn't happen all the time, I believe it's like 50-50 chance that the Mac will restart.

Possible reason:

I did a close watch and believe that the reason might be like this. Because the Blackmagic eGPU doesn't have a power switch, it will automatecally turn off if no Mac is connected. So during the restart, there is a short moment when Mac doesn't send data to eGPU, so the eGPU will power itself off. And Mac will think the external monitor is disconnected. Since it is on clamshell mode (lid closed), it will not boot.

I tried rebooting the Mac with lid open (and eGPU connected), and everything is totally fine. This could prove that it's not a hardware issue of the Mac.

To temporarily solve this, I have to take the Mac out of the vertical stand, open the lid and wait until apple logo shows, then close the lid. The Mac will reboot normally.

I tried to connect a keyboard to the Mac through eGPU's USB port. And tried to press any buttons to boot the Mac if it won't reboot. But it doesn't work since the eGPU itself is powered off it wont send the keyboard signal to the Mac. I havn't tried to connect the keyboard directly to the Mac yet, but even if it works I prefer not to solve it like this. Because I don't want to add another cable to the Mac.

Anyone who has the same issue and/or the solution please let me know please!