Unable to fetch finalised block

[Aideepakchaudhary]

I'm trying to print the finalised_block hash inside exex using this code:

if let Some(..) = notification.committed_chain() {
        if let Ok(Some(finalized)) = this.ctx.provider().finalized_block_num_hash(){
          info!(
                        "Finalized block number: {}, hash: {:?}",
                        finalized.number, finalized.hash
                    );
        } else {
          info!("No finalized block information available.");
        }
      }

and I'm running the exex with this command: cargo run --bin block-logger -- node --dev --http in dev mode. where block number only increase when a new txn hits. After running the above command, I can see the finalised block 0 every time.
Is this because I'm running in dev or I'm missing something?

Also if i run the exex with holeskey, then it first start syncing with other nodes and importing the blocks. During this process i don't see any log from the exex. Do i have to wait till full synchronisation and then perfrom txn to see the exex logs?