The Bug
Villagers who seel enchanted gear may sell it too high level. This can very easily be said with Fletcher Villagers.
Steps to Reproduce

1. It is best if you have the Bedrock Tweaks Trading Helper Resource Pack enabled
2. Summon a villager by any means
3. Give it a fletching table
4. View the expert level trade (Enchanted Bow)
5. Repeat this as many times until you get OP enchantments on the bow (Unbreaking III, Infinity, Power 3, Punch 1, Flame)

Expected Result
The villager should sell a bow that has a lower enchantment level

Observed Result
The enchantment level is beyond level 22. This can also be said with other enchanted gear from villagers.