Hi and thanks for reaching out. My name is Jan an independent Microsoft Advisor and a user like you. I'll be happy to help you out today.
Some of the keys might be stuck or not functioning properly. It can be the Windows key as it triggers the "connect display" function when you press K.
Windows key + K is the shortcut key for wireless display connection.
Try to test your keyboard here. Pressed keys will be highlighted red.
Mouse, touchpad, and keyboard problems in Windowshttps://support.microsoft.com/en-us/help/17417/windows-mouse-touchpad-keyboard-problems
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.