Hello, I’m Virginia an independent advisor with 20 years of expertise in fixing my own & friends’ PC problems.
Which Windows 10 build are you running - 1903, 1909 or 2004?
Was there any Windows or driver updates before the loss of Bluetooth?
Is there a physical switch or key on the keyboard which disables WiFi & Bluetooth?
If your Bluetooth is disabled then do the following to enable it.
Uninstall the device from device manager and restart bluetooth service.
Start > services.msc
Right-click "Bluetooth Support Service."
Choose Automatic.
Go to device manager and right-click on your computer name and click "Scan for hardware changes"
Install the bluetooth device drivers from the manufacturer's website, if any.
I hope this helps.