Hello IISYNll thank you for getting in touch with us and welcome to The Division forums.
I can see that a lot of these bugs you have listed are actually feedbacks on game mechanics and suggestions to improve them.
For the particular FX Mod Slots mod slot you mentioned, which are the 3 FX mods you are unable to obtain? Will they not unlock for you, or do you mean they do not appear in the game at all? If you could clarify this for me, I would be very thankful.