Thanks that was a good tip for me.

It says:
2020-08-14T07:53:14Z Added connection to 127.0.0.1:50698 peer=10
2020-08-14T07:53:14Z connection from 127.0.0.1:50698 accepted
2020-08-14T07:53:14Z PROCESSMESSAGE: INVALID MESSAGESTART version peer=10
2020-08-14T07:53:14Z disconnecting peer=10
2020-08-14T07:53:14Z Cleared nodestate for peer=10

Getting that output I assume the protocol version is wrong. But checking with getnetworkinfo:
{
  "version": 200000,
  "subversion": "/Satoshi:0.20.0/",
  "protocolversion": 70015,
  "localservices": "0000000000000409",
  "localservicesnames": [
    "NETWORK",
    "WITNESS",
    "NETWORK_LIMITED"
  ],
  "localrelay": true,
  "timeoffset": 0,
  "networkactive": true,
  "connections": 0,
  "networks": [
    {
      "name": "ipv4",
      "limited": false,
      "reachable": true,
      "proxy": "",
      "proxy_randomize_credentials": false
    },
    {
      "name": "ipv6",
      "limited": false,
      "reachable": true,
      "proxy": "",
      "proxy_randomize_credentials": false
    },
    {
      "name": "onion",
      "limited": true,
      "reachable": false,
      "proxy": "",
      "proxy_randomize_credentials": false
    }
  ],
  "relayfee": 0.00001000,
  "incrementalfee": 0.00001000,
  "localaddresses": [
  ],
  "warnings": ""
}


The protocolversion seems the same.