Same issue.
eDP-1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis)
344mm x 193mm
DP-1 connected 1920x1080+1366+0 (normal left inverted right x axis y axis)
480mm x 270mm
00:02.0 VGA compatible controller: Intel Corporation HD Graphics 5500 (rev 09)
(prog-if 00 [VGA controller])
Subsystem: ASUSTeK Computer Inc. HD Graphics 5500
Flags: bus master, fast devsel, latency 0, IRQ 50
Memory at b1000000 (64-bit, non-prefetchable) [size=16M]
Memory at c0000000 (64-bit, prefetchable) [size=256M]
I/O ports at 4000 [size=64]
[virtual] Expansion ROM at 000c0000 [disabled] [size=128K]
Capabilities: <access denied>
Kernel driver in use: i915
Kernel modules: i915
4.9.0-3 works, 4.9.0-4 causes flickering after a while when a key is pressed.
