Renaming an item after enchanting it

When I went to enchant my diamond pickaxe it costed way more than it should had

What I expected to happen was...:

I thought it was only going to cost like 1 - 2 levels of EXP

What actually happened was...:

But was actually worth 35 levels of EXP

Steps to Reproduce:
1. Enchant an weapon in 1.15.2
2. Use an anvil
3. Rename the enchanted item