Can't turn on Bluetooth, Bluetooth adapter disappeared both in Device Manager and the Hidden Devices in Device Manager

Thank you. This just saved me from a low Wife Acceptance Factor for the new build. (GB B550i AX Pro here). 

She kept telling me she couldn't see any of her Cameo (vinyl cutters) anymore and Bluetooth was just gone, and until I had a chance to look at it today I didn't quite believe her.  But after the ratrace of not even finding the hidden devices, re-running the downloads from the manufacturer all acting like the module didn't even exist, I was tearing my (nonexistent) hair out.

Any idea what makes the module just drop out? Static shock or overheating putting it into a shutdown protect mode and never coming back on its own?  (As with others here, the Wifi never stopped working....)  EDIT - never mind, reading on about the power settings....

I think it is Gigabytes fault. Something is disabling the Bluetooth on normal computer shutdown inappropriately. Not surebut Gigabyte has not answered my emails or phone calls???

Thank you. This just saved me from a low Wife Acceptance Factor for the new build. (GB B550i AX Pro here). 

She kept telling me she couldn't see any of her Cameo (vinyl cutters) anymore and Bluetooth was just gone, and until I had a chance to look at it today I didn't quite believe her.  But after the ratrace of not even finding the hidden devices, re-running the downloads from the manufacturer all acting like the module didn't even exist, I was tearing my (nonexistent) hair out.

Any idea what makes the module just drop out? Static shock or overheating putting it into a shutdown protect mode and never coming back on its own?  (As with others here, the Wifi never stopped working....)  EDIT - never mind, reading on about the power settings....

Similar issue here with Aorus Master B550.

Seems to be a motherboard issue. I temporarily fixed mine by the following:

1. shutdown the computer
2. disconnect power (turn off, remove plug)
3. press the power on button on your computer (to ensure the power is drained to on-board capacitors etc) - at least 10 seconds
4. reconnect power
5. startup

For me, this reliably restores the Bluetooth device and Windows can then turn Bluetooth on/off and the device appears in Device Manager.

Same issue here as the OP, just saying this resolved it for me :-)

Pulling the cord was the key, no amount of rebooting or anything else I tried worked

I don't know what to tell you about this issue (I also had this issue on a Gibabyte Aorus B550i Mini iTX AMD motherboard). What did fix mine ( I Think) was eventually doing the total shutdown, remove power plug etc and of course removing any Bluetooth Devices after showing hidden devices. 

This fix I tried several times to only have it disappear after turning my PC off it would always fail but somehow as of late for the past couple weeks it is fixed. 

Also to note I downgraded my motherboards BIOS to version F2 for my board.

Unfortunately my good luck lasted only a few days and the device has dissappeared again. The usual power off, unplug, drain the power by trying to turn on, then turn on and restart works ok.

This problem seems related to dropping into and out of standby. I have never lost the device whilst the PC is operating. Also, I never fully shutdown the PC so I don't think it is related to the full power off sequence.

Given that this issue occurs on different motherboards from different manufacturers, and that Intel hints at an issue with the device with standby, I suspect this is an Intel driver or hardware issue.

What can be done to get this properly fixed, otherwise, this amounts to selling a defective product and there should be some consumer remedies (depending on your jurisdiction of course).