Chain.so is not a miner. If your transaction is not in anyone else's mempool (and determining this is impossible to do), then your transaction will not be mined. You can remedy that by rebroadcasting the transaction to the network so that it does enter all nodes' mempools, but it may drop out of them again later, so you would have to rebroadcast again later.
Thank you. What happened to me was, the transaction(5225cff0ac48fa59ff85553cb515e21560abbcdd0711f1179f8cd189a792d121) had been on Chain.so for 48hours while no other block explorers were showing it. However, a day later, that transaction finally went through. Any thoughts on what was happened?
Now I have another one in the same situation. No one is showing it except Chain.so
0a031d2e72904b7d90cc6de55f913b489be2613f9b5acd43a5cd5158d1cf7c76