How to setup HDMI output and multiple monitors on AMD switchable graphics (Enduro)?

Question

AMD

There is a monoblock Lenovo Ideacentre B550 . It has two graphics cards - "integrated" Intel HD Graphics 4000 and "discrete" AMD Radeon R9 M270X.
Installed Windows 8.1 64 bit, all drivers from the official site.
There are two HDMI connectors on the back of the monoblock, labeled In and Out. When connected to the In connector of a video source (checked by connecting a laptop and a DVD player) and pressing the hardware (regardless of the PC status) Input button, the monoblock "monitor" switched from the built-in PC to an external HDMI input and showed the image from the input. There is no problem here.
It was necessary to urgently connect a projector to this monoblock.
And here are the figurines. The system stupidly does not respond to a device connected to HDMI Out. The second monitor does not appear on Windows. The projector is 100% working, from the laptop the video goes fine via HDMI to the projector.
Updated drivers for both Intel HD Graphics and damn AMD. No effect. The Catalyst Control Center lacks everything pertaining to a multi-monitor configuration.
Question - what could be the matter?
The variant with a faulty HDMI output disappeared after testing in a neighboring office on exactly the same monoblock.

Answer 1

The problem was solved only after changing the OS to Windows 7. A specialist came with a monitor calibrator for calibration. The software for calibration stupidly hung and did not see the monitor. There was no time to figure it out. We quickly rolled Windows 7. And everything worked out. Under the seven everything works like clockwork.