I share the same problem with many of the commenting individuals here. My laptop keyboard stops responding after 1 second of responding, and it stops responding for about a second before it starts to respond again. In other words, 1 second of responding, then 1 second of NOT responding, then responding again, in a cycle and at a very regular pace.
This issue renders the keyboard very useless. Any external keyboard (including Bluetooth keyboards) works excellently; it's just the laptop keyboard that has the issue.
I tried reinstalling the keyboard and all its components, uninstalling Norton Antivirus, toggling various basic keyboard settings, starting the computer in safe mode, and installing all the recommended updates from the Dell website. I can't roll back system updates because I just bought this computer, so it has no history. I bought it refurbished.
Dell Inspiron 13 5000 2-in-1, Windows 10