Tablet - iOS - iPad Mini
How to perform this enchant bug.
Step 1: Have enchanted iron sword in inventory
Step 2: have non-enchanted iron sword in inventory
Step 3: enchant iron sword
Step 4: Realize this is a bug
So those are the steps on how to lose items enchants (step 4 not included)
MCPE-10281 Enchantments on items disappear