I hope I have properly identified this problem.

In my application I start vMix (along with 2 other programs) by placing them and mYProgram.vmix in the Startup folder.

I use several Function keys to choose various PTZ virtual inputs and my hope was to automate the program so that untrained volunteers could run the system by simply powering up the computer. Except the shortcut keys don't work!

Even though the vMix window covers up the windows of the other 2 programs it apparently does not have focus and seemingly unless the vMix window is the active window the shortcut keys won't work.

So you have to let everything boot up, then click anywhere on the vMix window, then the shortcuts all work. If you click over to one of the other programs you lose the shortcut function in vMix.

I suspect this is a Windows feature and I can see how if you had two active programs that both used shortcuts it might be necessary to have the shortcut package follow focus. Still in my case it's a bummer.

One workaround is to use https://www.autohotkey.com/ with which you can direct needed keys to the vMix application. (Implies that those keys cannot be used in other applications).