Did you broadcast manually via Bitcoin Core or using an external website like coinb.in?
If you do it via Bitcoin Core, it should show the error code and description for why your transaction was rejected.
"Status: 0/unconfirmed, not in memory pool, has not been successfully broadcast yet"
This is generally indicative that, while you transaction is "valid",a theternal node(s) your wallet is attempting to broadcast to is rejecting the transaction and refusing to relay it.
Common causes are things like min-relay-fee not met, or dust outputs, or possibly it is just using a UTXO that is unconfirmed and at the end of a long chain on unconfirmed transactions etc.
Next time, try using the debug console (Help -> Debug window -> console) and "sendrawtransaction" within Bitcoin Core to see the reason your transaction is being refused.