I got a strange behavior on my hackintosh.
When I have an active connection between my Samsung S8 & samsung app smart switch for syncing then my keyboard is somehow disabled. I cannot use any letters, only a few keys with the special characters ^and ´ are working. After disrupting the active connection the keyboard is still in this "mode". It does not go back in normal functioning I have to restart the computer.
The app without my phone connected and only my phone connected to my computer without starting the app does not cause my keyboard to this behavior.
On my macbook with the same Mac OS Mavericks I don´t have this behavior. It works just fine.