Unless I have read the op wrong, it appears you are setting the ohms on the Alien manually to the declared ohms on the coil. Therefore the Alien will keep changing the ohms of the coil to what it actually is, which most of the time is not what is stated on the coil. Setup the coil as above, and leave it at that. Gunk build up and other things affect the coil ohms as well, and the Alien may well pickup that same change and adjust as ness.
As for the Alien it's only doing it's job, another "better" mod, will do the same. It will register the ohms of the coil at what it is, and not what it should be, and adjust a ness. if there is a notable change in the ohms.
PS. Factor in the fact that Smok coils are not world beaters as well.
Disclaimer: I'm not against Smok, currently using the Smok majesty and cloud beast.