Auto-correcting a word@1.1
In an existing contenteditable with “Hello World” in it, putting the cursor at the end of the editor, type isnt  and let it auto-correct (presumably) to isn't ending in Hello World isn't  with a space at the end. Note if auto-correct did or did not happen.

Chrome (Desktop)

no auto-correct.

Safari (Desktop)

auto-correct.

Firefox (Desktop)

No auto-correct.

Android API 28

Auto-correct.

Android API 27

Android API 26

Android API 25

Android API 24

Android API 23

iOS 11.4