I'm doing something wrong with change address, but don't know what.

[oshirowanen]

Can someone please explain what is happening here?

Note: Everything done on testnet so the only value lost was time.

In this first screenshot:

https://i.imgur.com/8WXKdgb.png

it shows that:

1 I am making a payment to mwCwTceJvYV27KXBc3NJZys6CjsgsoeHmf

2 I am sending change to mogwtVo5bDzJRWsVNLEpfDDt5dXHcC2tf5 <- cold wallet address.

The second screenshot shows extra translation fees being calculated:

https://i.imgur.com/yRzxf8v.png

The third screenshot shows the change going to a completely different address, change went to n18wMXVBXoE134AQsd7GcQKnjBah2MsPdD

https://i.imgur.com/564PKIi.png

I have tested this twice, and twice the change went to an address other than the address I specified.

What's going on?

[1714951350]

1714951350

[ranochigo]

AFAIK, Bitcoin Core is set to ignore change address if the address is not from the wallet. The reason for this is to prevent users from sending an amount that is too high to the change address since you do not specify how much is spent there.

This is a known behavior by Bitcoin Core even though it can be confusing. If you want to specify change to another address, use pay to many and do it manually.