Are you running the 32-bit or 64-bit version of OBS? Have you tried switching to the other?
Apparently, some headset providers have software to control the headset, and in the case of Razer hardware, it only appears in the 64-bit version of OBS. However, when closing out of the software for the headset (using Task Manager to close it out), 32-bit OBS can detect and use it just as well.
It could be a similar issue. Another possibility is that you only have 32-bit or 64-bit drivers available for your hardware - not both. You'd have to figure out whether it's detected in the other OBS build, and if so... that's likely your issue.