When we made item with Enchantment, at the Frost Walker enchant, If that EnchantMent over 14 levels, The Ice-Generate Range doesn't change more.

LV1 - 6 block
LV2 - 8 block
LV3 - 10 block
LV4 - 12 block
LV5 - 14 block
LV14 - 32 block
~
LV20 - 32 block
~
LV200 - 32 block
~
LV255 - 32 block

Is that a bug? or it Work-as-intended? 
If that is Work-as-intended, How does it work? Limit on Game? Bug of the Code? etc.