When I connect an external display while the Surface is already turned on, the external display is flickering. When I restart the Surface with the external monitor already attached everything works fine. Disconnecting the Surface then and reconnecting - same problem. The flickering appears with different monitors, different cables and with different connectors (Surface Dock or USB-C). I have the 16 GB, i7 Version of the Surface 7 with an up to date OS.
I have the exact problem with my brand new surface pro 7, i7, 16gb. Hooking up two external monitors via mini dp to dp cables through the surface dock. OS is updated, surface dock is updated. Registry cleared/updated.
The really weird thing is that i use the exact set up with my older surface book 1 without any problems. So definitely not the set up.
I love the SP7, but will likely have to return it because of this.