Qualcomm Atheros AR3012 Bluetooth not working in Windows 10

Here is how I made the AR3012 working again on Windows 10 20H1.

1. remove AR3012 & its drivers completely from 20H1, later let 20H1 detect it as Generic Bluetooth Radio.
2. download Qualcomm driver v10.0.1.15 from Microsoft Catalog website, install this driver via driver upgrade.
3. after v10.0.1.15 being installed, you might see additional device named in "Bluetooth LE" as the one in the Kirill's figure.
4. try to connect any BT device you couldn't connect after upgrading to 20H1, make sure the AR3012 really WORKS.
5. then download any Qualcomm driver v10.0.3.x (as Kirill mentioned, the newest one is v10.0.3.22, or let Windows Update do it later), upgrade  the driver of AR3012 again with this one.

Notice: NEVER uninstall the v10.0.1.15 while/after upgrading to v10.0.3.x, or the AR3012 will fail again after reboot.

Microsoft Generic Bluetooth Driver -> Qualcomm BT driver v10.0.1.15 -> Qualcomm BT driver v10.0.3.x,

if you did followed the steps, your AR3012 should be working as usual, even after reboot. 

Qualcomm Atheros Communications - Bluetooth - 10.0.1.15 (x64)

Qualcomm Atheros Communications - Bluetooth - 10.0.3.22 (x64)

I guess the "Bluetooth LE" is the critical point of this issue.

(I DID hate the crappy W10...... what's M$ doing now? let users recall how windows unstable in 1990s? )

NOTE by MELERIX: by the way, as it is an older driver, it does not support the new Windows 10 shutdown mode called fast startup*, so every time you shut down Windows and then restart it, the device appears with an error, so you have to* disable the fast startup of Windows 10*, in the power options of the control panel.*