Whenever you switch from an enchanted item to an unenchanted item the enchantments transfer for just a second.

Whenever switching between items their properties are not meant to overlap

i was playing on survival and went to cut some trees. I switched from my fully enchanted pickaxe to an iron axe and it instantky broke the log (normally it takes some time for it to break)

Steps to Reproduce:
1. hold an enchanted item for example: a diamond pickaxe with efficiency 5
2. switch to an axe/shovel and quickly try to break a log/dirt
3. if done right the axe/shovel should break the block as fast as if it had efficiency 5