X370 Taichi - bluetooth dead but WIFI works???

I know this a day late and a dollar short, but I have seen this on Dell Laptops too. I find the most common cause is the WiFi/BT Card.Make sure the Computer is off, remove the screw holding it in place, remove the card and make sure the metal contacts are clean, then reinsert the card and screw back in place. most of the time this will resolve it more permanently unless you get up and go with your desktop often, then it may come slightly loose or change position in it's slot causing the issue to reoccur.

Since several weeks I have the integrated Bluetooth adapter that stoped working. It is no more listed in the Device Manager. At its place is a unrecognized USB device.
I tried many workaround and finally succeed to make it working.
The motherboard is an ASROCK X370 Taichi.
Here is the list of all my changes that may not be all needed.
1) Update of the bios to P4.80
2) In the bios I set the BT adapter to ON.
3) After booting the computer I installed the Intel BT driver V20.70.0.4
4) In the device manager I install manually a Microsoft Wireless Wifi router.
5) Then I shut down the computer and remove the power for 5 minutes.
6) At start up I change the BT option in the bios to AUTO.
Miracle, after booting, in the device manager the BT adapter is recognized!

My pleasure, I passed many hours before finding that trick.My Bluetooth link is still working hopefully
The Bluetooth/Wifi board is removable as I was able to change it under warranty (the 5 GHz was not working). You need to remove the board from the computer to access the screws on the bottom side. Removing the white plastic cover above the rear connectors is needed in the process.
But I do not know if the BT/Wifi board form factor is standard.

it worked for me after hours of trying different solutions in vain. I registered in purpose to thank you from the future (September 2021) :O)