[MC-86932] Knockbock Attribute no longer working

when you give yourself an Iron Sword like this

/give @p minecraft:iron_sword 1 0 {AttributeModifiers:[{AttributeName:"generic.knockbackResistance",Name:"generic.knockbackResistance",Amount:1,Operation:1,UUIDLeast:894654,UUIDMost:2872},{AttributeName:"generic.movementSpeed",Name:"generic.movementSpeed",Amount:-0.35,Operation:1,UUIDLeast:894654,UUIDMost:2872}]}

the Knockback Resistance seems to no longer work properly.