Solution (Copied from another thread):   I am just assuming you are all on QCA9377 ??  This has been a known bug with this Card though Drivers were released for this issue however they fix it temporarily.  - Please disconnect power cable   - Force Shutdown using power button and keep holding it for 15 seconds  - You will have your Bluetooth back However there is no Guaranty how long will it work.  In my case it broke after a few Months.   Permanent solution : Swap the card with an intel Card  
Hello,  Started up a game on my PC which crashed then had a windows blue screen error. On restarting I still have functioning WiFi but no Bluetooth icon in the bottom right toolbar system shortcut.  I restarted as a first attempt to fix but this didn't work so I followed windows online troubleshooting steps (Bluetooth troubleshooter-->Not detected-->Checked drivers-->No drivers-->Installed Drivers-->Still not appearing in Device manager). Then went into My Dell Support App-->Hardware Troubleshooting to test the network card and the test just said failed (no info about what in particular failed). Skeptical it is a problem with the hardware as the WiFi is still working fine.  Retried installing all the drivers on Dells site relating to the network card and an that caused a new problem of the Killer WiFi app not opening (although WiFi is still fine).  Any help would be greatly appreciated.  Thanks, Will   System: XPS 17 9700 OS: Edition Windows 11 HomeVersion 21H2Installed on ‎30/‎10/‎2021OS build 22000.1098Experience Windows Feature Experience Pack 1000.22000.1098.0    
Bluetooth driver/network card fail