Some of the regularly used Bitcoin wallets, for example, the Bitcoin Core wallet and the Electrum Bitcoin Wallet, set the locktime of newly constructed transactions to the current block height. This is as an anti-fee-sniping measure and visible as a stair-like pattern when plotting time-locked transactions by their mempool arrival time and locktime. The plot, however, reveals transactions time-locked to a future block height. These should, usually, not be relayed through the Bitcoin network.
