Hi friend,
Be sure to advise people to read and understand the WARNING appear after they've encrypted their wallet.
https://imgur.com/mhwPvUl
I've found a Vietnamese document here advise very clearly how to safe guard your wallet:
https://file.io/s4J82d
IN BRIEF: LET DELETE YOUR OLD WALLET BACKUP THOROUGHLY, because if other people have your un-encrypted wallet, they can spend your FUND easily.
I see many Vietnamese having other people install the wallet for them, if installer copy un-encrypted wallet than this will be a DISASTER!

It's not wallet bug, every wallet tell you the same and keep yourself SAFE is your OWN RESPONSIBILITY

VERY VERY CAREFUL ABOUT THIS and please share with other if they don't know
Regards
FOL