"mathematical Fraktur small k" is broken

[curya]

As the title says, "mathematical Fraktur small k" is not appearing correctly:

It should look like this:

The bold version is also affected:

[Mercury13]

@curya Maybe I’ll find a new font for the entire Fraktur math. I use Cambria for now, as title says.

[curya]

Why not Noto Math?

[Mercury13]

Why not Noto Math?

Probably too big metrics, IDK.

[kenmcd]

This form from Cambria Math is the most widely used. Not sure why, but it is. This form is what is in the official Unicode Code Charts. This form is in STIX Two Math. This form is in all the TeX Gyre math fonts. This form is in MathJax Fraktur. So this may be the expected form.

Minion Math does not have those fraktur characters. So I guess they would come from another font. The old Lucida Bright Math symbol fonts do not have those characters. But the Lucida Blackletter font does have the same form as NotoSans Math. So Noto Sans Math is the only math font I have found with that form. Yes, it is more recognizable, but why is the other form used more? And used in the Unicode Code Charts?

Would be interesting to see what form is used in published books. I agree the Noto Sans form is more recognizable to non-math people. But is it what math-people expect?

[Mercury13]

Blackletter K is so rare that I probably won’t find anything. Fraktur k actually looks this way, interesting.

[Mercury13]

I’m a post-Soviet man familiar with advanced maths. And blackletter K in our country would look somehow simpler. But we have no Gothic tradition, of course.

[Mercury13]

Right now I’ll just write: Some Fraktur letters are barely recognizable. Both Unicode charts and most fonts, including Windows and TeX, are designed this way, though some mathematicians, especially in non-Latin countries, use simpler fonts.