I did that and it only wasted my bitcoins. This feature doesn't work.
You have to set a fee that is high enough for 2 transactions. So maybe you didn't set a high enough fee.
The problem is even worse: None of transactions got refunded! The destination (receiver - to whom i wanted to pay) bitcoin addresses were changed in the meantime and all my bitcoins are lost. I didn't get any refund. Only balance disappeared.
If the transactions confirmed then it is not the fault of electrum or the bitcoin network. The fault now lies with the recipient. Just because they gave you a different address for your NEXT transaction doesn't mean that they no longer control the address from the previous transaction. So take this up with them. Send them a link to the relevant page on a block explorer to show them that you have paid.
