M4 Pro Mac Mini w/ Apple Touch ID keyboard w/ numeric key pad. Plugged in (NOT USING WIRELESS). Tahoe 26.2
Turn Caps Lock On, light shows, no caps when typing. Shift key works fine. Caps when holding down shift key. Tested wirelessly as well, same thing. Restarted. No change. Checked the various keyboard settings, and all seem correct. Caps lock key is NOT remapped. In keyboard settings, with picture of keyboard, when I hot caps lock, the keyboard picture changes to caps. 99.9% of searching found caps lock won’t shut off or stuck.
Also try power-cycling the keyboard (I added that line in a later edit, so it may not have appeared in the e-mail response).
I’m thinking that the microcontroller in the keyboard has glitched and therefore needs to be reset. I’m hoping that the power switch will be sufficient to reset that controller. If that doesn’t do it, then I’m not sure if there will be another way.
I just turned off my caps lock because my mechanical keyboard doesn’t indicate when it is on, causing password issues. Maybe try turning caps lock off and then on again.
Have you tried booting in Safe Mode and then entering text with Caps Lock on? If the problem remains, there is a basic OS or hardware issue with your Mac. If it disappears, then check your optional extensions and login items.
Always a good test, but I don’t think it is the problem here, because the rest of the keyboard functionality is working. A bad cable would cause everything to be flaky/broken, not just CapsLock.
I concur. The problem is not likely to be in the keyboard. I suppose it might be possible for two different keyboards to both fail in the same way, but I would tend to doubt it.
A good test, to rule out possible interference from some system extension.
Also, consider creating a new non-admin user account, log-in to that account, and run your tests. If it works fine from there, then it is almost certainly some preference or configuration file or background app causing the problem. It might take some time to figure out which one, but at least you’ll have a starting point from which to being your analysis. The analysis will go something like:
Disable one feature (log-in item?) on the misbehaving account. Then log out/in and test again to see if the problem goes away. Repeat until you find the culprit or go through everything.
and/or
Add one feature/configuration to the new account. Then log out/in and test again to see if the problem appears. Repeat until you find the culprit or go through everything.
Also, check to see if any Accessibility preferences might be interfering. Make sure all the Accessibility → Keyboard options are disabled (unless you actually want to use one of them). Also look at Accessibility → Switch Control. And maybe skim through all the other Accessibility options to make sure nothing unexpected is turned on.