Unreal 5.4.1 Blackmagic Decklink Input-Output not working simultaneously

[WEFSflipfactory]

Running Unreal 5.4.1 with Blackmagic Decklink in windows 11. (latest drivers)

I am able to load the basic virtual production template project and setup video input and output with the decklink card, however they will only function separately and not simultaneously.

I can hit the capture button and output the cinema camera via SDI to my monitor but if i try to enable the input mapping nothing will happen.

I can turn off the output and then enable the input and the SDI video will popup and appear in my scene, but then if i try to hit the capture button to output to my monitor nothing happens.

And again if i disable the input mapping then the output works again.

Any idea if there is some setting that is causing this problem?

I do have a clue as to something that might signify an issue. When i enable the input mapping and it appears in my scene then Unreal also automatically loops that SDI input video to the SDI output.
This should not be happening, the output should be blank until i send something to it. I believe this is why when i try to output myself nothing happens because Unreal is using it already to loop out the input so the device is locked in use and i cant output to it.
Conversely the same thing is happening in reverse, When i have the output working, then i try to enable the input it doesn’t work because it wants to use the output also but that is in use already.

Thanks

[comlys (Shaun Comly)]

This looks like a bug. We’ll file a JIRA and get this looked at. Thanks for reporting it!

[WEFSflipfactory]

And just to be clear, after further testing I determined that this is only happening on machines we have the Decklink Studio 2 card in. Another machine with Decklink 12G Extreme card works as expected. Multiple machines I tested with the Decklink Studio 2 card do not work.

I have also reported this on the Blackmagic forum, however they have not responded.