i can confirm, there is a bug in 3.10.0.95 where if opera is running in the background nvidia geforce experience / shadowplay doesn't work. Recording, streaming options don't start at all.
Exiting opera allows geforce experience to start recording.
Windows 8.1
I5 4570 + gtx 1060

Opera devs should work with nvidia for a resolution.

I had this problem, when my router wasn't stable enough.
With time, they come less dependable. What i said might have nothing to do with your issue though.

Video recording proof: https://www.youtube.com/watch?v=fSSEcogbky0

Version information

Version: 46.0.2597.46 (PGO) - Opera is up to date
Update stream: Stable
System: Windows 8.1 64-bit