Why is my no-durability perk not working as it should?
This is a two part answer:
Some items do not receive the normal "no-durability" perk obtained from the veteran role. That is because these items have their own specific durability reduction via skills. They include but are not limited to prim weapons, tools, etc.
We turn off durability in certain situations to prevent it from being too overpowered and broken. Such situations include things like certain high end monuments, Zombie Island, and most PVP or raid situations. It would not be fair if a veteran could raid an entire base with just a jackhammer or run an entire monument with an explosive ammo SAR and never lose a single thing. This is intentional and is not going to change.