Windows 10 v1903, dGPU on graphics intensive app

[stvlada]

So I had few rounds of installing Windows Insider Previews on my computer and it worked fine until last update. After that I've lost WiFi option and no network settings at all. However, my internet worked if I'm connected through the TCP cable but that was not an option. Therefore, I had to reinstall Windows 10 yesterday and I've used most recent ISO
Windows 10 1903 b 18362.329

Now I'm experiencing problems not being able to start different apps if my laptop screen is not set as a main display. Usually my laptop screen is "disconnected" and I'm running two external monitors.

We need urgent fix on this as I'm not willing to spend hours reinstalling my Windows again due to bad Insider Preview patches.

EDIT:
Particular issue is with Viber app (viber.com).
My laptop has two GPUs, Intel 530 and nVidia GTX 960. By default most of the apps are handled by Intel 530.
To workaround this I had to do Right click on the app > Run with graphic processor > High-performance nVidia processor.
This way I managed to start Viber app.

Microsoft hasn't resolved this issue fully, so please address it further and one more time. This is really critical.