How to resolve freezes when pressing caps lock on external keyboard

I've been trying to diagnose a problem with my Logitech K120 keyboard paired with a Macbook Pro 15" (Retina, 15-inch, Late 2013) where occasionally, pressing the caps lock would cause that keyboard to completely stop responding for a few seconds. I'd previously used this keyboard with a Windows PC, and found no issues.

I've tried the following:

  1. Setting the modifier key to do nothing and then setting it back (per this Superuser answer)
  2. Installing Karabiner Elements (from the same Superuser thread. This actually makes it worse, in that when the keyboard freezes the computer, it never unfreezes until I kill Karabiner

Has anyone encountered this before? I might just try replacing the keyboard soon, but I was hoping there'd be a software or configuration fix that would work.


Solution 1:

This has happened to me on two different Macs with 3 different bluetooth keyboards. Two Apple keyboards and one Logitech. The symptom is always the same, intermittently the keyboard will freeze for about 5 seconds after hitting the caps lock key.

Restarting the computer will often resolve the issue for a short time but an SMC reset normally resolves the issue more long term.

I have had this experience over the last 5 years and have found documentation of others having the exact same issue for over a decade. It's obviously a larger underlying issue and I'm not sure why it persists.