[saadat]

In your iMessage screenshot, this character is being rendered in Noto Nastaliq Urdu[1], which is a font that uses the nastaliq flavor of the Arabic script (as compared to the more widely used naskh flavor, which you're most probably seeing in Chrome's rendering).

What's curious to me is that Apple only uses Noto Nastaliq Urdu if Urdu is enabled in preferred languages and is higher than any other Arabic-script language. [2] Is that so on your machine?

[1] https://fonts.google.com/noto/specimen/Noto+Nastaliq+Urdu?pr... (There's a slight difference in the placement of diacritics here because of a newer font version.)

[2] https://support.apple.com/guide/mac-help/latin-fonts-correct...

[ivanbakel]

In some discussion about Arabic rendering on another website[0], it was pointed out that the Basmala is its own codepoint in part because it is (or was?) a legal requirement on Pakistani documents and comes from an Urdu character-set. It's possible that, as a character effectively originating from and used by Urdu speakers, Apple defaults it to Nastaliq regardless of your font settings.

0: https://lobste.rs/s/7s4sjp/u_fdfd_arabic_ligature_bismillah_...

[saadat]

Ah!

Or, it could be that out of all system fonts on MacOS, only Noto Nastaliq Urdu has a glyph for the bismillah, and thus the system uses it as a fallback...