I bought a replacement Razer Naga Pro after my existing one had many issues with its scroll wheel (scrolling was inconsistent and bad, middle mouse click was inconsistent, and left and right buttons on it didn’t work at all). I used the mouse pairing utility and it still did not work with the dongle. It worked with the cable, and it worked via bluetooth, but the dongle refused to work despite the pairing utility telling me that it was working fine.
I eventually figured out that I should upgrade the firmware. After upgrading the firmware and pairing it, it worked flawlessly. There are support threads here about the pairing utility not working but they were all solved via private messages, so there was nothing for people to read and troubleshoot theirselves. I feel like there should be something somewhere letting people know that they need to update their firmware to get the damn thing to work.