nvidia capture sdk hangs when capturing to hw encoder

The nvidia capture SDK provides a dwTimeoutMs option for capturing to system memory, for capturing to cuda and also for capturing to GL.

So it is possible to use blocking capture, and the timeout ensures the capturing does not hang.

BUT there is no dwTimeoutMs option for capturing to the hardware encoder.

And because there is no timeout, blocking capture using the hardware encoder hangs if the screen is not updated.

Can someone please help me understand why there is no dwTimeoutMs for the capture to hardware encoder?

At the moment, my code hangs.