It's either the gas is not enough or the network is busy. It is also the same as the bitcoin where I read a thread that the transaction is not confirmed due to low fee. Try to check your wallet address in the etherscan if you can see a transaction that has not been processed when you send the transaction.
The problem does not have to do with the gas and it also not the as Bitcoin network congestion but I believe it either the problem is from the OP when he sent the transaction which possibly makes the transaction, not to reach the mempool and that's the reason why the Etherscan cannot present the transaction information cause it is not available on the mempool.