Question 2nd Monitor lights up at BIOS but afterwards it doesn't work ?

[AlchoRe]

I've got a problem with my 2nd Monitor. It is connected via a HDMI to VGA connector. (HDMI Output from my GPU)

So basically when I turn on my PC the Monitor lights up and shows the Motherboard / BIOS Logo. But after it boots up to Windows only the one monitor works, the other one doesn't show up.

I tried almost everything to fix it. But it just doesn't work.
Any Ideas?

Please I need this Monitor for Work.