I am using a cold wallet and made a few tx two days ago. However, though what I wanted to send was a very small amount of btc, the wallet made multiple utxo of huge amounts get involved and now all my assets are locked up as the tx are unconfirmed.
- Why does a wallet have to use multiple utxo (input>output 2>2 or 3>2) rather than just use one and split it in two (1>2)? (the aimed tx amount is smaller than each utxo)
- Is the algorithm to select which utxo specific to each wallet or is there any general rule throughout bitcoin network?