Actually....it's stopped working again about an hour after I posted the above. Uggh. :(
This is driving me crazy. It has always worked (it=hold a key down, the key repeats). Until last night. Worked again for a few minutes earlier today, then back to this.
Yes, I can get the key to repeat pretty much all of the non-alphanumeric characters by holding down the key, eg
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But any letter or number.....................................................nope.
OK, I have been testing different use cases, and now I am seeing something strange....
To be clear: the behavior I have always seen in this (and dozens of other Macs) has been: hold down any key, the character repeats. That was the behavior in all apps. This suddenly stopped working last night, and it started working -- briefly -- today, now it's now longer working.
Now, I'm getting the "glyph-picker" popup shown in Tom Gewecke's post above -- but not consistently. It depends on the app I'm using.
In the Finder, in MS Word, in TextEdit, in Safari (which I'm using to type this), when I hold down a key, I'm getting either a single character (in most cases) and I get the glyph-picker popup for a specific set of characters.
In all Adobe apps (InDesign, Photoshop, Illustrator -- I use them a lot) the behavior is different:
Those characters which would (apparently) pop up the maOS glyph-picker (the following characters: a, c, e, i, l, n, o, s, u, y and z) actually DO repeat when a key is held down. Other characters do not repeat.
So it seems that Adobe does not invoke the same OS-supplied glyph-picker popup (makes sense for many reasons) and just treats the held-down-key differently.
But I am quite sure that before something changed yesterday, the behavior was consistent, in multiple apps, including InDesign, Photoshop, Illustrator (when things briefly started "working" for me today, I was testing in TextEdit, and I would hold the 'x' key down, the x-character repeated as long as I held down the key).
I've done some cursory google searches for this issue and there are a LOT of Mac users reporting similar behaviors. So I'm not sure what to think.
I do have this question, though:
Open up the Keyboard settings on your Mac. Note the presence of the slider labeled "Delay Until Repeat".
If holding down a key is not supposed to work, what is the purpose of this setting?
Given Apple's weird fetish for removing EVERYTHING they possibly can, why would this legacy setting still be allowed to exist?