strange issue with different imports from javax and google guice

I have noticed that when i use

@com.google.inject.Singleton

on a Class, it will be somehow inject a different instance than when i do the javax import of it.

So Class1 has the google Singleton import and has: "@Inject Class3". Class 3 would be "instance1"
and Class2 has the javax Singleton import and has: "@Inject Class3". Class 3 would be "instance2"

Maybe it is intentional but from what i saw in several docs, it should inject the same thing. (yes it is singleton). Same result when i call a method on both classes and use 3x "injector.getInstance(Class3.class), it would return the singleton but would somehow create one instance per javax and one per google import