uninitialized enum variable value

An enumeration is not constrained to take only the declared values.

It has an underlying type (a numeric type at least large enough to represent all the values), and can, with suitable dodgy casting, be given any value representable by that type.

Additionally, using an uninitialised variable gives undefined behaviour, so in principle anything can happen.

Because those variables are uninitialised; their values are indeterminate. Therefore, you're seeing the result of undefined behaviour.