Cannot acquire multi-enchanted items

On 1.21, I type */give MCheping8108 minecraft:crossbow[minecraft:enchantments={levels:

{"power":1}

,levels:{"punch":1},levels:{"unbreaking":255},levels:{"flame":1},levels:{"multishot":8},levels:{"quick_charge":255}}]* and press Enter, but only one quick_charge, I have no install mod and influence Minecraft plugins, take a look, please