I had my Razer Nari Ultimate for a few years now and it worked without any problems.
Last week it suddenly lost connection and also disappeared in Synapse. I tried to reinstall/repain Synapse but it didn’t help. When I tried the Razer Nari Ultimate Pairing Utility-Tool it reconnected but disconnected as soon as it played a sound. My headset works with my Laptop for multiple hours without any problems. The last days I tried the Pairing Utility-Tool again now it works and plays sound but disconnects after about 10 Minutes.