Yup, I have the exact same issue here, having both entered the code for Specialisation Priority Alpha as well as owning the Limited Edition. I'm currently still an SR-43, so hopefully they'll unlock before I hit 50.
It happens on and off for me, however; before redeeming the code I could view all of them. After redeeming it (which was on Monday maybe?) I could only see Wetwork and Operator. Last night I could view all the specialisations for some reason, but today when I booted up the Xbox it was back to Wetwork and Operator.
