Here is official document : Unity - Scripting API: MonoBehaviour
Focuse the top lines :
OnEnabled() ?
Are you kiding me ?
MonoBehaviour is so important ! OnEnable() is important , but the doc is wrong .
The right name of the callback method is “OnEnable()” !
I hava spent 2 hours to check the problem : OnEnable() not called.
Because in my script, I use OnEnabled() !
Thanks for misleading me by “Official Document”.