@Mathijn hej, I really didn´t find out the problem. I got no feedback and I got tired of this issue. I moved on to another distro. I might come back in the future.
I suppose it is some kernel problem. I got it after upgrading from 4.3. A new installation didn´t solve my problem.
But this forum is really dead… better try your luck at the official arch forum. But don´t mention you are using antergos…they will close the topic immediately. :)
P.S. I read your post again and I understood you like to help. :) Well, I have a dell e7440 notebook. Intel i5 haswell. I am using an external Monitor with DP-connection and an external USB3-hub.
Beside that I can not see any interesting speciality. I did try to reboot without any external devices to no avail.