Because it is hard coded to be this way.
WZ\src\EclipseStudio\Sources\UI\UIItemInventory.cpp
Code:
void UIItemInventory::addTabTypes()
{
Scaleform::GFx::Value var[8];
var[2].SetNumber(0);
var[3].SetNumber(0);
var[4].SetNumber(0);
var[5].SetNumber(0);
var[6].SetNumber(0);
var[7].SetBoolean(true); // visible in store
// store & inventory tabs
var[0].SetNumber(0);
var[1].SetString("weapon");
var[2].SetBoolean(true);
var[3].SetBoolean(true);
gfxMovie_->Invoke("_root.api.addTabType", var, 4);
var[0].SetNumber(1);
var[1].SetString("ammo");
var[2].SetBoolean(false); <------ CHANGE TO (true)
var[3].SetBoolean(true);
gfxMovie_->Invoke("_root.api.addTabType", var, 4);
Code:
// special category for ammo
var[0].SetNumber(419);
var[1].SetString("ammo");
//var[2].SetNumber(1); <--- remove two //'s at front of line
var[2].SetNumber(0); <--- add two //'s at front of line
var[3].SetNumber(-1);
gfxMovie_->Invoke("_root.api.addCategory", var, 4);
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