If Bluetooth driver is missing or gets removed after a Windows Update, add the legacy driver from the Device Manager, install the correct driver from your manufacturer, etc.

Repeat delay: Controls the time delay before a keystroke repeats when held down. Repeat rate: Determines the speed of repeated keystrokes. Press the Windows key, type Device Manager, and hit Enter.

Windows disconnects idle devices if power-saving options are enabled. This could be the reason why your mouse or keyboard keeps disconnecting. Here is how you can turn off power-saving options: ...