I'm getting the same issue too. To reproduce I:

1. Have Opera running Netflix and watching a show.
2. Open Nvidia overlay on the dektop, select Instant Replay, and choose "Turn On"
3. Replay does not turn on
4. Close Opera entirely
5. Open Nvidia overlay on the dektop, select Instant Replay, and choose "Turn On"
6. Replay does turn on

I just tried this and had the same issue while running Netflix. I posted a reply that's pending approval. That said, I did the same thing with Chrome and it actually behaved exactly the same way. That is to say, Netflix seems to be turning off Instant Replay. I wonder if this is an Nvidia- or OS-level feature to avoid having record content and redistribute it.

I'm getting the same issue too. To reproduce I:

1. Have Opera running Netflix and watching a show.
2. Open Nvidia overlay on the dektop, select Instant Replay, and choose "Turn On"
3. Replay does not turn on
4. Close Opera entirely
5. Open Nvidia overlay on the dektop, select Instant Replay, and choose "Turn On"
6. Replay does turn on