Hello, thank you for reaching out to Microsoft Q&A.
Have you tested whether the keyboard works properly when connected to another device?
This will help determine whether the problem is with the keyboard or with the Bluetooth settings.
Since the mouse is working properly over Bluetooth, the keyboard is probably the issue.
- If the wireless keyboard comes with a USB dongle, plug it in, ensure the batteries are inserted, and make sure the keyboard is powered on.
- Once the USB dongle is plugged in, Windows should automatically detect the keyboard and add it to the list of devices.
That way, we can at least confirm that the keyboard is working.
If you are still having issues,
*Share the model of your Dell Keyboard.
Then, see if you can pair and connect it with another device successfully. (if you have one).