External monitor not waking

[bab5139]

When i plug in my 2018 macbook pro (closed) into an external monitor using usb-c/thunderbolt 3, the external monitor will not turn on. Only when I open the mac book does everything come to life. Then i can close the macbook and the external monitor will work fine. This started happening 3-4 weeks ago. Anyone else having this problem?

 

[deadworlds]

In my experience I also need to have the power plugged in.

 

[macIsShit3000]

I have the same issue! The power is plugged in (almost all the time) so that's not the problem!
Monitor always stays off unless I unplug/plug the adapter.
This is extremely annoying