My apologies if this has been fixed in v4.39, as I haven't tested that yet. But here's the issue I ran into.
I was trying to render some smoke using Octane Volume with a VDB sequence. Octane viewport glitches out on the first sample and constantly goes between 0 and 1 samples forever. The moment I turn off the volume object in my scene, the viewport renders normally.
I fixed this issue by re-installing v4.16 for the shot, and everything worked fine. Fortunately, installing different versions is really easy. I just wanted to let someone know that this was an issue I ran into. Perhaps I had some sort of setting wrong that was causing this glitch, but I didn't change any settings when reverting to an older version and it rendered just fine.