-snip-
How my various wallet.dat files got mixed up I do not know. I feel there is a security issue here somehow. Its up to the technical guys to evaluate that.
Your screenshots show that your wallets aren't "
HD" (
Hierarchical Deterministic)
so if you ever made too many transactions after the first backup (
used all addresses up to the last key in the keystore), it will contain outdated list of addresses.
Loyce's reply is true except your new addresses wont differ with a password change, it will only happen the first time you encrypted the wallet.
AFAIK, they had been recommending to frequently backup your wallet.dat file back when Bitcoin Core's wallet isn't HD.
That may be the reason why you got multiple copies of the same wallet.
Congrats BTW.
