Thanks @Vitor Pamplona! @Michael ⚡️S⚡️ I can confirm that the keyboard is working on non-compose text fields. It looks like this is a bug in Compose UI framework; or with the keyboard when dealing with Compose text fields.

Indeed, it only happens with Compose. But it is a well-known bug in old keyboard implementations like AOSP's default keyboard. Lots of applications have had this issue. And since nobody is updating those old keyboard codebases, I don't think this will be solved anytime soon.