prime-switch needs to reboot to work using gdm

[Nicholas]

System: Kernel: 4.13.0-041300-generic x86_64 (64 bit)
           Desktop: Gnome 3.24.2 Distro: Ubuntu 17.04
Graphics: Card-1: Intel Device 5916
           Card-2: NVIDIA Device 179c (GeForce 940MX)
           Display Server: X.Org 1.19.3 drivers: modesetting (unloaded: fbdev,vesa)
           Resolution: 1366x768@60.00hz
           GLX Renderer: Mesa DRI Intel HD Graphics 620 (Kaby Lake GT2)
           GLX Version: 3.0 Mesa 17.1.8
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Using GDM for the display manager results on gnome not starting, neither from intel-> nvidia nor from nvidia-> intel.
The workaround that I found was installing lightdm for default display manager.