HLG monitoring is black from Blackmagic Decklink 4K 12G using HDMI

[vortexiv]

Premiere Pro v22 (b169)   I am unable to monitor HLG sequences (either HD or UHD) with HLG content thru a Decklink 4K 12G (ver. 12.2.2) .  The monitor "sees" a signal but remains black, reporting UHD HLG with a BT.2020 gamut.  If I toggle the sequence's Working Color Space to Rec709 an image appears and the monitor switches to Rec709 and drops out of HLG.  The same thing happens if I toggle the Decklink's color gamut preferences to Rec709 within Premiere's Preferences/Playback/Video Device settings. So I know the Decklink is sending a signal.

The same UHD HLG content plays back flawlessly thru Blackmagic's Media Express software.

I've run out of things to try, switches to flip. In case you're wondering, I dont have a HDR monitor with SDI inputs so I can't try that.

[R Neil Haugen]

Ouch!

Have you tried the LiftGammaGain forum or CreativeCow? Might be someone there with an answer too.

Neil4

[vortexiv]

Didn't find any info on this particular issue, will follow up with Blackmagic.

[Andy 1968]

I would download and older version of Desktop Video from Blackmagic Design's website. If that does not work contact Blackmagic Design. 

[vortexiv]

I rolled back to the first Desktop Video drivers that supported HDR and then moved forward with no luck, same black output.  Will reach out to BM.