When enchanting an overleveled enchantment book on an anvil with an item, will cap the enchant at the max survival obtainable level

So earlier today, I was experimenting around with the new components change for commands. I gave my self an Unbreaking IV enchantment book and I wanted to see what would happen if I were to combine it with a diamond sword in an anvil. The result was an Unbreaking III diamond sword instead. I was confused, so I tested it on a lot of other over leveled enchantment levels like Protection VIII and got Protection IV; Density X and got Density V; and Mending III and got Mending I. I'm very sure this bug works on any other over leveled enchantment book.

Note: Tried these experiments on both Creative and Survival Modes and got the same results

Please fix this, it would help mapmakers put over leveled enchantments as some form of loot in their maps and be able to combine it onto an item properly.

Steps To Reproduce The Bug:

1. Generate a new world with cheats. Doesn't matter if its creative or survival mode.

2. Go into chat and type the command: /give @s minecraft:enchanted_book[minecraft:stored_enchantments=
   {unbreaking:4}
   ] In the parenthesis you may add an enchantment with a high level above the vanilla one. I used unbreaking 4. Examples: density:10, protection:10, mending:6, sharpness:6 etc.

1. Get an anvil and a sword or any item with the over leveled enchantment you chose.

2. Combine the overleved enchantment book with the item and you should see in the results that the enchantment caps at the max survival obtainable level

Observed Results:

enchanting an overleveled enchantment on an item will cap at the max survival obtainable level of that enchantment

Expected Results:

Combining an item with an over leveled enchant will give the newly enchanted item the same level as said in the enchantment book