In VirtualBox, when RDP connecting via iPad, the image is streamed to the RDP host over the lock screen. How to fix?

Question

virtual box

On a Windows 7 x64 PC
I have a Windows 7 x32 virtual machine running in VirtualBox 5.2.18.
(In the virtual machine, the Extension Pack and guest additions are installed, 3D acceleration is enabled.)
There is also an iPad on which the Microsoft Remote Desktop application is installed.
The iPad connects via the Microsoft Remote Desktop app to the virtual machine via RDP.
The connection is successful, the VM screen is locked, and the VM desktop is displayed on the iPad.
The problem is as follows:
If I launch the 3D application (Game), then a black screen is displayed on the iPad screen and only the mouse cursor is active.
In this case, the image of the game itself is broadcast over the lock screen on the virtual machine (although it should have been transmitted to the iPad).
(The game itself works fine in a virtual machine.
If you run the game on the main OS and connect to it via RDP through the iPad, everything works correctly.)
How can I fix it?

Answer 1

Some kind of crap with the video settings in the virtual machine ...
As I understand it, 2d-3d acceleration is in it?
In general, broadcasting games via RDP is not normal)