My Razer Kaira is full of hate

The Kaira Pro headset had been working very well with my Xbox Series X for a few months. However - I just bought a new gaming PC... And when the built-in Bluetooth wouldn't function on my PC... I bought the "Xbox Wireless Adapter for Windows 10" that is specified in the Kaira Pro user manual. It won't connect, period. I have tried for two hours, scouring every corner of the internet before coming here to find another person had a thread describing the exact same issue. Of course - that thread from April won't allow any further replies and it had no help for the issue. Windows is up-to-date. Firmware is up-to-date on the Kaira Pro headset. Drivers are up-to-date on the Wireless Adapter for Windows 10. I can find no way to "unpair" the headset from my Series X. When you hold down the pairing/power button until it flashes (pairing mode)... It either turns on my Xbox for me, or (once the Series X is totally unplugged from power outlet) the headset stays in pairing mode forever. It will not connect to PC even after spending more money to buy the adapter. Xbox Wireless Controller can connect successfully to PC using the same Adapter. In addition to the obvious steps you take when trying to pair devices...I have tried "forgetting" every other Bluetooth device on the PC, restarting Windows, and then tried again. I am out of ideas. I do have surround sound speakers and a crumby Bluetooth headset (used for voice chat only) which I can use on the PC for now.... But I bought the gaming headset specifically so I could have both in one device, and I chose this model because it specifically told me I could switch between Xbox and PC... There is a review for the Kaira Pro online touting how easily the reviewer was able to switch between them. Any help is much appreciated from the Razer community here. Thank you.