View Blockchain Explorer http://www.stes.tyc.edu.tw/xoops/modules/profile/userinfo.php?uid=3670142 So, when there is a large number of transactions while in the mempool therefore you paid out a relatively lower transaction cost, your transaction can continue to be unconfirmed for an extended time frame considering that miners/validators will pick out transactions with bigger fees firs... https://bookmarkja.com/story23410951/blockchain-explorer-confirmed-transactions-a-review-of-explorer-blockchain-ethereum-https-cutt-ly-3rj9ygbc