@Aron-Sjöberg
My config below:

@Aron-Sjöberg Used sketch below, I didn't make any changes to the original sketch:

/**
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2015 Sensnology AB
 * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * DESCRIPTION
 * The ArduinoGateway prints data received from sensors on the serial link. 
 * The gateway accepts input on seral which will be sent out on radio network.
 *
 * The GW code is designed for Arduino Nano 328p / 16MHz
 *
 * Wire connections (OPTIONAL):
 * - Inclusion button should be connected between digital pin 3 and GND  
 * - RX/TX/ERR leds need to be connected between +5V (anode) and digital pin 6/5/4 with resistor 270-330R in a series
 *
 * LEDs (OPTIONAL):
 * - To use the feature, uncomment WITH_LEDS_BLINKING in MyConfig.h
 * - RX (green) - blink fast on radio message recieved. In inclusion mode will blink fast only on presentation recieved
 * - TX (yellow) - blink fast on radio message transmitted. In inclusion mode will blink slowly
 * - ERR (red) - fast blink on error during transmission error or recieve crc error 
 * 
 */

#define NO_PORTB_PINCHANGES  

#include <MySigningNone.h>
#include <MyTransportRFM69.h>
#include <MyTransportNRF24.h>
#include <MyHwATMega328.h>
#include <MySigningAtsha204Soft.h>
#include <MySigningAtsha204.h>

#include <SPI.h>  
#include <MyParserSerial.h>  
#include <MySensor.h>  
#include <stdarg.h>
#include <PinChangeInt.h>
#include "GatewayUtil.h"

#define INCLUSION_MODE_TIME 1 // Number of minutes inclusion mode is enabled
#define INCLUSION_MODE_PIN  3 // Digital pin used for inclusion mode button
#define RADIO_ERROR_LED_PIN 4  // Error led pin
#define RADIO_RX_LED_PIN    6  // Receive led pin
#define RADIO_TX_LED_PIN    5  // the PCB, on board LED

// NRFRF24L01 radio driver (set low transmit power by default) 
MyTransportNRF24 transport(RF24_CE_PIN, RF24_CS_PIN, RF24_PA_LEVEL_GW);
//MyTransportRFM69 transport;

// Message signing driver (signer needed if MY_SIGNING_FEATURE is turned on in MyConfig.h)
//MySigningNone signer;
//MySigningAtsha204Soft signer;
//MySigningAtsha204 signer;

// Hardware profile 
MyHwATMega328 hw;

// Construct MySensors library (signer needed if MY_SIGNING_FEATURE is turned on in MyConfig.h)
// To use LEDs blinking, uncomment WITH_LEDS_BLINKING in MyConfig.h
#ifdef WITH_LEDS_BLINKING
MySensor gw(transport, hw /*, signer*/, RADIO_RX_LED_PIN, RADIO_TX_LED_PIN, RADIO_ERROR_LED_PIN);
#else
MySensor gw(transport, hw /*, signer*/);
#endif

char inputString[MAX_RECEIVE_LENGTH] = "";    // A string to hold incoming commands from serial/ethernet interface
int inputPos = 0;
boolean commandComplete = false;  // whether the string is complete

void parseAndSend(char *commandBuffer);

void output(const char *fmt, ... ) {
   va_list args;
   va_start (args, fmt );
   vsnprintf_P(serialBuffer, MAX_SEND_LENGTH, fmt, args);
   va_end (args);
   Serial.print(serialBuffer);
}

  
void setup()  
{ 
  gw.begin(incomingMessage, 0, true, 0);

  setupGateway(INCLUSION_MODE_PIN, INCLUSION_MODE_TIME, output);

  // Add interrupt for inclusion button to pin
  PCintPort::attachInterrupt(pinInclusion, startInclusionInterrupt, RISING);


  // Send startup log message on serial
  serial(PSTR("0;0;%d;0;%d;Gateway startup complete.\n"),  C_INTERNAL, I_GATEWAY_READY);
}

void loop()  
{ 
  gw.process();

  checkButtonTriggeredInclusion();
  checkInclusionFinished();
  
  if (commandComplete) {
    // A command wass issued from serial interface
    // We will now try to send it to the actuator
    parseAndSend(gw, inputString);
    commandComplete = false;  
    inputPos = 0;
  }
}


/*
  SerialEvent occurs whenever a new data comes in the
 hardware serial RX.  This routine is run between each
 time loop() runs, so using delay inside loop can delay
 response.  Multiple bytes of data may be available.
 */
void serialEvent() {
  while (Serial.available()) {
    // get the new byte:
    char inChar = (char)Serial.read(); 
    // if the incoming character is a newline, set a flag
    // so the main loop can do something about it:
    if (inputPos<MAX_RECEIVE_LENGTH-1 && !commandComplete) { 
      if (inChar == '\n') {
        inputString[inputPos] = 0;
        commandComplete = true;
      } else {
        // add it to the inputString:
        inputString[inputPos] = inChar;
        inputPos++;
      }
    } else {
       // Incoming message too long. Throw away 
        inputPos = 0;
    }
  }
}

@Aron-Sjöberg I would guess the problems are due to the CH340G chip (instead of an FTDI chip). I use this nano for my gateway:
https://www.aliexpress.com/item/Nano-V3-0-Mini-USB-ATmega328-5V-16M-100-ORIGINAL-FTDI-FT232RL/32338360936.html?spm=2114.13010608.0.0.ZU4WHD

@Aron-Sjöberg I can configure both ports at the same time. It looks exactly as in the posted picture.

@BartE I justfollowed the instructions on the website. This was probably a year ago and the code used for the serial GW was designed only for Arduino Nano 328p / 16MHz.

@Aron-Sjöberg
My config below:

@miro
I've got this one
https://www.kjell.com/se/sortiment/dator-natverk/datortillbehor/usb-tillbehor/usb-hubbar/plexgear-usb-3-0-hubb-4-vags-p61062

It's been up running for a year now.

@Aron-Sjöberg Did you solve your problem? I have a mysensors serial gateway, a rfxtrx433e and a USB stick connected to my Vera (Edge) through an externally powered USB hub (plexgear). They all work just fine.