If the Power Management tab doesn't exist in the device properties right click on the Qualcomm Atheros QCA6x4 Bluetooth device with a yellow exclamation mark or similar, "Disable device" then "Enable device". This actually brings back the bluetooth manager and your paired devices should connect (for a short term fix until the next hibernation when it decides not to turn the device back on), but it also also brings the Power Management tab in the device properties.
Note: I never had to turn off and on the bluetooth device in the bios.
I had the same problem. My Bluetooth would die for no reason leaving me keyboard and mouseless. The imminent fix to get Bluetooth working again was to poweroff the laptop and disable and re-enable the Bluetooth device in BIOS. That worked for a couple hours maybe a day. Then I was back to rebooting and going into the BIOS. I have a long-term workaround/fix, which is to disable management for the Bluetooth device.
- open "Device Manager"
- Select "Bluetooth" on the device tree
- find the "Qualcomm Atheros ..." Bluetooth controller
- double click on "Qualcomm Atheros ..." device
- select "Power Management" tab
- uncheck "Allow the computer to turn off this device to save power"
My new bluetooth Microsoft Surface Keyboard was disconnecting constantly and this seems to have fixed it.
To help others find this, my setup is a 9560 XPS 15 with the Intel WiFi and Bluetooth chip.
Are you saying to delete and reinstall the software? I haven't used BT in months and just found the same problem. It's missing from Device Manager but that software is installed. A plain reboot didn't work.
Oops, missed the previous poster's comment. Trying it now.