DeckLink 4K Extreme 12G - Internal Keyer?

I tried to make a DeckLink 4K Extreme 12G to work in internal keying mode today. I set the keyer to "internal" and sent an SDI signal into the first (3rd BNC from top) input. It did not work. Useing the older DeckLink 4K Extreme that was working like that, if I remeber right. Does anybody know if that card has an internal keyer?
Didi Kunz
CasparCG Client-Programmer, Template Maker & Live CG-Operator
Media Support, CH-5722 Gränichen, Switzerland
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