I was not familiar with dendritic salt, so I looked it up.
"Morton Salt is the only manufacturer of dendritic salt. Star Flake® Dendritic Salt is a high purity, food grade salt formed in porous, star-shaped modified cubes. Its unique and diverse physical properties result in low bulk density, a rapid dissolving rate, exceptional flow characteristics, strong blendability, unmatched liquid adsorption and a quick, salty sensation."
This is from the Morton Salt company website.
Do you have a link that explains why you think the salt will fix the scent? (maybe I just missed that info when researching the subject)
Most FOs/EOs intended for use in CP soap will not require a fixative. Unless you use citrus EOs.
But, I would look to the salt for the explanation of what is happening. The rest of your recipe looks fine. I would do a batch with no salt or clay, then one with no clay, then one with no salt just to confirm if it is either of those, and how your scent sticks or not with and without those.