The problem: I call a smart contract function on my local blockchain, then I confirm the transaction on metamask and finally the transaction is submitted but the transaction does not get mined.
On the blockchain console I receive the warning below:
WARN [03-26|18:21:48.169] Served eth_sendRawTransaction conn=127.0.0.1:60092 reqid=1559115320157 t=213.552µs err="already known"
Instead, when I disable metamask and I send a transaction with the unloacked account then the transaction get mined.
The strange thing that it used to work, I made many operations since yesterday.
Do you have any clue? Thanks!