Have you tried going into Blackmagic's control panel and set the 'Set default video standard as" to HD 1080p 23.98? It should automatically change for you but just in case.
Yes, I tried changing that to several things (including HD 1080p 23.98) and restarting in between, but it didn't seem to make a difference.
Ok this is definitely a bug. Out of frustration and sheer luck from doing so many combinations I got it to work (temporarily). There was a 23.976 sequence that wasn't transmitting to the external monitor. I unchecked Blackmagic in the playback preferences, quit, reopened the project, re-checked BM in preference, and the same sequence that didn't work before, worked.... until I created a new sequence. The new sequence not only didn't work, it broke the sequence that was just working 5 seconds ago.
I've uninstalled/restarted/reinstalled/restarted the BM 9.7.5 drivers with no difference.
I have seen some sync issues on atleast 1 Blackmagic card and maybe another with 24 frame stuff. The way I had to solve it was turn off the display for a short period and turn on again and then maybe minimize Premiere and Maximize again if the first didn't work. Sounds like you found another way to force the BM to re-sync.
Ok, this is getting ridiculous. The behavior is completely inconsistent. Once I get it to recognize a 23.98 sequence, no other sequence works. Sometimes the monitor goes to sleep and wakes up repeatedly, as if it's getting an intermittent signal.
Now when it is displaying something, Premiere won't give up control. I can switch to finder and the last frame stays up on the monitor (even though "Disable video output when in the background" is checked. It won't even let AE have control, so now AE playback doesn't work either.
I have tried a different HDMI monitor - same behavior
I have tried a different HDMI cable - same behavior
I have tried the Intensity Pro in a different PCI slot - no change
ECBowen, turning the monitor off/minimizing Premiere doesn't do anything on this end. Thanks for the response, though.
Whose issue is this - Adobe or Blackmagic? Creative Cloud is not usable for me and I'm nervous because we're about to roll it out on 6 machines.
Any other ideas??
At this point I would have to say the issue is with BM's new firmware update. It definitely is a sync issue and like you said it's intermittent though I was able to reproduce it almost every time on a Flanders LM2461W with a Blackmagic 4K card. Even Davinci was showing it as well. Turning off the Monitor fixed Davinci.