When you give yourself for example a diamond axe with a special attribute is attack speed of 1, you don't get it. Instead it gives you a diamond axe with no attack speed.

 

How to reproduce:

/give @p diamond_axe{Unbreakable:1,AttributeModifiers:[

{Slot:"mainhand", AttributeName:"generic.attack_speed", Amount:1, UUID:[I; -1, -1, -1, -1]}

]}