I have the same issue as well! Seems like many of Razer Nari Ultimate users have been facing this issue recently. Just started a thread here: 

Same here! I was using my headphones fine and in the middle of a game the headset disconnected and haven't been able to get it to connect again for more than 6 seconds. I had a similar issue a couple months ago, I read that it was a pairing issue and downloaded the paring utility given by razer and it fixed the problem. Not this time unfortunately. Sometimes it will recognize the dongle, most of the time it wont. when I am able to make it through the pairing utility and the headset actually connects, it will disconnect again whenever I try to start a video or even open up a google chrome tab. I've tried everything online, reinstalling all razer software and trying to check drivers but it never stays connected long enough to do so. I tried to submit a support ticket only to be told the headset I bought a year ago is no longer under warranty. Very frustrating, I love razer and have never had a problem paying a bit more for the brand. However if a $200 headset wont even last me a year, I'm going to lose confidence in purchasing a product from them in the future. I hope there is a fix in the future, I can still use a 3.5mm aux cable, but I bought a wireless headset for a reason. I would buy another dongle if it was the issue and not software based but they don't sell it as far as I can tell. If anyone has a fix I haven't tried or knows where to get a new dongle so I can try that I would greatly appreciate. the last thing I want is to leave the cult of razer but its starting to look like I'm going to be forced.