electrum.network.TxBroadcastServerReturnedError

Hello, I using electrum with api on my linux machine, eveything worked fine until I got an error few days ago after broadcasting my transaction in logs:

Code:

[2020-03-06 12:43:04] ov.error: Api return error
{
   "curl": {
   "http_code": 200,
   "response": "{\"result\": null, \"id\": \"1583487784599\", \"error\": {\"code\": -d, \"message\": \"Server error: File \\\"/usr/local/lib/python3.6/dist-packages/electrum/network.py\\\", line 806, in broadcast_transaction | electrum.network.TxBroadcastServerReturnedError: Unknown error\\n\"}}"
   },
   "data": {
   "id": "1583487784599",
   "method": "broadcast",
   "params": {
   "tx": "02000000000000001...770900"
   }
   },
   "url": "http://xx.xx.xx.xx",
   "api_error": {
   "code": -32603,
   "message": "Server error: File \"/usr/local/lib/python3.6/dist-packages/electrum/network.py\", line 806, in broadcast_transaction | electrum.network.TxBroadcastServerReturnedError: Unknown error\n"
   }
}

[2020-03-06 12:43:04] ov.error: Api return error
{
   "curl": {
   "http_code": 200,
   "response": "{\"result\": null, \"id\": \"1583487784678\", \"error\": {\"code\": -32603, \"message\": \"Server error: File \\\"/usr/local/lib/python3.6/dist-packages/electrum/network.py\\\", line 783, in wrapper | electrum.network.UntrustedServerReturnedError: The server returned an error.\\n\"}}"
   },
   "data": {
   "id": "1583487784678",
   "method": "gettransaction",
   "params": {
   "txid": "b7af19...59425d7"
   }
   },
   "url": "http://xx.xx.xx.xx",
   "api_error": {
   "code": -32603,
   "message": "Server error: File \"/usr/local/lib/python3.6/dist-packages/electrum/network.py\", line 783, in wrapper | electrum.network.UntrustedServerReturnedError: The server returned an error.\n"
   }
}

After ~15 minutes it finally broadcasted and tx appear in blockchain, but I can't understand what cause the problem and why it takes much time with errors. Undecided

Any help is appreciated.