I’m a dummy. Can I swap gpu s in my Core X?

I have gotten my AMD RX6900XT card running perfectly. I have an Nvidia Quadro K6000 that I know is good, but I can’t get it to run. I’m at this point; I can boot cleanly into windows only with the amd and my m1200 uninstalled, when the K6000 is enabled. Then I get a frozen POST image on my external monitor and that’s it. I don’t have synapse or cortex installed. I have been at this for months and this is the first time I’ve gotten this far. Razer and Nvidia have both pointed at the other. The drivers and os are the latest available. Both cards aren’t listed as supported. Any suggestions would be appreciated. There’s extenuating circumstances for wanting to do this. Thanks Bill